Language：English   Publishing type：Research paper (international conference proceedings)  

Electron Acceleration at a High Beta and Low Mach Number Rippled Shock

DOI： 10.1088/1742-6596/642/1/012017

Other Link： http://iopscience.iop.org/1742-6596/642/1

Language：English   Publishing type：Research paper (scientific journal)  

Simulations of pickup ion mediated quasi-perpendicular shocks: Implications for the heliospheric termination shock

DOI： 10.1002/2013JA019654

Language：English   Publishing type：Research paper (scientific journal)  

Dynamics of energetic electrons in nonstationary quasi-perpendicular shocks

DOI： 10.1029/2012JA017986

Other Link： http://www.agu.org/pubs/crossref/2012/2012JA017986.shtml

Language：English   Publishing type：Research paper (scientific journal)  

Relativisitic particle acceleration in developing Alfven turbulence

DOI： 10.1088/0004-637X/742/1/47

Other Link： http://iopscience.iop.org/0004-637X/742/1/47/

Language：English   Publishing type：Research paper (scientific journal)  

Microstructure of the heliospheric termination shock: Full particle electrodynamic simulations

DOI： 10.1029/2011JA016563

Other Link： http://www.agu.org/pubs/crossref/2011/2011JA016563.shtml

Language：English   Publishing type：Research paper (scientific journal)  

Mach number dependence of electron heating in high Mach number quasiperpendicular shocks

DOI： 10.1063/1.3372137

Other Link： http://link.aip.org/link/?PHP/17/042901

Language：English   Publishing type：Research paper (scientific journal)  

Relativisitic particle acceleration in developing Alfven turbulence

DOI： 10.1088/0004-637X/692/2/1004

Other Link： http://iopscience.iop.org/0004-637X/692/2/1004

Language：English   Publishing type：Research paper (scientific journal)  

Pickup protons at quasi-perpendicular shocks: full particle electrodynamic simulations

Other Link： http://www.ann-geophys.net/25/283/2007/angeo-25-283-2007.html

Language：English   Publishing type：Research paper (international conference proceedings)  

On reformation of quasi-perpendicular collisionless shocks

DOI： 10.1016/j.asr.2004.08.012

Other Link： http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V3S-4KBVX01-5&_user=131115&_coverDate=12%2F31%2F2006&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_acct=C000009658&_version=1&_urlVersion=0&_userid=131115&md5=db06e0aac2e4423229c0217f

Repository Public URL： http://hdl.handle.net/2324/16887

Language：English   Publishing type：Research paper (scientific journal)  

On microinstabilities in the foot of high Mach number perpendicular shocks

DOI： 10.1029/2005JA011409

Other Link： http://www.agu.org/pubs/crossref/2006/2005JA011409.shtml

Repository Public URL： http://hdl.handle.net/2324/16894

Language：English   Publishing type：Research paper (scientific journal)  

Coherent waveforms in the auroral upward current region

DOI： 10.1029/2004JA010477

Other Link： http://www.agu.org/pubs/crossref/2004/2004JA010477.shtml

Repository Public URL： http://hdl.handle.net/2324/16895

Language：English   Publishing type：Research paper (scientific journal)  

Modified two-stream instability in the foot of high Mach number quasi-perpendicular shocks

DOI： 10.1029/2003JA010080

Other Link： http://www.agu.org/pubs/crossref/2003/2003JA010080.shtml

Repository Public URL： http://hdl.handle.net/2324/16885

Language：English   Publishing type：Research paper (scientific journal)  

Parametric instabilities of circularly polarized Alfvén waves in a relativistic electron-positron plasma

DOI： 10.1103/PhysRevE.67.046406

Other Link： http://pre.aps.org/abstract/PRE/v67/i4/e046406

Repository Public URL： http://hdl.handle.net/2324/16868

Language：English   Publishing type：Research paper (scientific journal)  

Nonlinear evolution of electromagnetic waves driven by the relativistic ring distribution

DOI： 10.1063/1.1431593

Other Link： http://pop.aip.org/phpaen/v9/i2/p649_s1

Repository Public URL： http://hdl.handle.net/2324/16867

Language：English   Publishing type：Research paper (scientific journal)  

Comparison between the Landau and Cyclotron Resonances in the Electron Beam-Plasma Interactions

DOI： 10.1143/JPSJ.68.1049

Other Link： http://jpsj.ipap.jp/link?JPSJ/68/1049/

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Physical Review E  

The interaction between a thin foil target and a circularly polarized laser light injected along an external magnetic field is investigated numerically by particle-in-cell simulations. A standing wave appears at the front surface of the target, overlapping the injected and partially reflected waves. Hot electrons are efficiently generated at the standing wave due to the relativistic two-wave resonant acceleration if the magnetic field amplitude of the standing wave is larger than the ambient field. A bifurcation occurs in the gyration motion of electrons, allowing all electrons with nonrelativistic velocities to acquire relativistic energy through the cyclotron resonance. The optimal conditions for the highest energy and the most significant fraction of hot electrons are derived precisely through a simple analysis of test-particle trajectories in the standing wave. Since the number of hot electrons increases drastically by many orders of magnitude compared to the conventional unmagnetized cases, this acceleration could be a great advantage in laser-driven ion acceleration and its applications.

DOI： 10.1103/PhysRevE.110.065212

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Publishing type：Research paper (scientific journal)   Publisher：Physics of Plasmas  

The mechanism of generating collisionless shock in magnetized gas plasma driven by laser-ablated target plasma is investigated by using one-dimensional full particle-in-cell simulation. The effect of finite injection time of target plasma, mimicking the finite width of laser pulse, is taken into account. It was found that the formation of a seed-shock requires a precursor. The precursor is driven by gyrating ions, and its origin varies depending on the injection time of the target plasma. When the injection time is short, the target plasma entering the gas plasma creates a precursor; otherwise, gas ions reflected by the strong piston effect of the target plasma create a precursor. The precursor compresses the background gas plasma, and subsequently, a compressed seed-shock forms in the gas plasma. The parameter dependence on the formation process and propagation characteristics of the seed-shock was discussed. It was confirmed that the seed-shock propagates through the gas plasma exhibiting behavior similar to the shock front of supercritical shocks.

DOI： 10.1063/5.0230232

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Publisher：Proceedings of Science  

Whistler waves are important in scattering and accelerating electrons in space. In the supercritical regime where the upstream Alfvén Mach number is above the so-called whistler critical Mach number, phase standing whistler waves can be excited and confined in the foot of the quasi-perpendicular shocks. On the other hand, in the subciritical regime whistler wave trains are emitted toward the upstream of the shock. However, the electron acceleration efficiency related with the whistler critical Mach number is not understood well. Here we report new results from several 1D particle-in-cell simulations of quasi-perpendicular shocks above and below the whistler critical Mach number. In the subcritial regime, the simulation showed that high energy electrons penetrate upstream, and the density profile is similar to the standard diffusive shock acceleration. On the other hand, in the supercritical regime, the high-energy electrons are generated locally in the narrow regin of the foot or overshoot magnetic field. This is similar to electron spike events at the Earth’s bow shock and interplanetary shocks. Our result will give a new insight into the understanding of electron acceleration at collisionless shocks.

Scopus

Publisher：Proceedings of Science  

The statistics of galactic cosmic rays (GCRs) invading the heliosphere are investigated using numerical simulations. First, a time stationary global heliosphere is reproduced using an MHD simulation. Then, motions of a large number of GCR protons with initial Lorentz factor 10 (∼ 10 GeV) and 1000 (∼ 1 TeV), distributed in the interstellar space around the heliosphere, are numerically solved. We map the positional distribution of the GCRs arriving at 50 AU from the Sun. Our results show that the arrival position of GCRs depends on their energies. We discuss the statistical behavior of the arriving GCRs at each energy.

DOI： 10.22323/1.444.1252

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Publishing type：Research paper (scientific journal)   Publisher：High Energy Density Physics  

We investigate the competition of magnetic reconnections in self-generated and external magnetic fields in laser-produced plasmas. The temporal evolution of plasma structures measured with self-emission imaging shows the vertical expansions and horizontal separation of plasma, which can be signatures of reconnection outflows in self-generated and external magnetic fields, respectively. Because the outflows in self-generated magnetic fields are not clear in the presence of the external magnetic field, the external magnetic field can suppress the magnetic reconnection in self-generated magnetic fields.

DOI： 10.1016/j.hedp.2024.101132

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Publishing type：Research paper (scientific journal)   Publisher：American Astronomical Society  

Abstract

The injection process of pickup ion acceleration at a heliospheric termination shock is investigated. Using two-dimensional fully kinetic particle-in-cell simulation, accelerated pickup ions are self-consistently reproduced by tracking long time evolution of shocks with an unprecedentedly large system size in the shock normal direction. Reflected pickup ions drive upstream large-amplitude waves through resonant instabilities. Convection of the large-amplitude waves causes shock surface reformation and alters the downstream electromagnetic structure. A part of pickup ions are accelerated to tens of upstream flow energy in the timescale of ∼100 times inverse ion gyrofrequency. The initial acceleration occurs through the shock surfing acceleration (SSA) mechanism followed by the shock drift acceleration mechanism. Large electrostatic potential accompanied by the upstream waves enables the SSA to occur.

DOI： 10.3847/2041-8213/ad5d73

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Other Link： https://iopscience.iop.org/article/10.3847/2041-8213/ad5d73/pdf

Publishing type：Research paper (scientific journal)   Publisher：American Geophysical Union (AGU)  

Abstract

Starting from 29 January 2022, a series of solar eruptions triggered a moderate geomagnetic storm on 3 February 2022, followed subsequently by another. Despite the typically minimal impact of unintense storms on space technology, 38 out of the 49 Starlink satellites underwent orbital decay, re‐entering Earth's atmosphere. These satellite losses were attributed to enhanced atmospheric drag conditions. This study employs numerical simulations, utilizing our test particle simulation code, to investigate the dynamics of the inner radiation belt during the two magnetic storms. Our analysis reveals an increase in proton density and fluxes during the transition from the recovery phase of the first storm to the initial phase of the second, primarily driven by intense solar wind dynamic pressure. Additionally, we assess Single Event Upset (SEU) rates, which exhibit a 50% increase in comparison to initial quiet conditions.

DOI： 10.1029/2023SW003789

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Physical Society (APS)  

Linearly Polarized Coherent Emission from Relativistic Magnetized Ion-Electron Shocks

DOI： 10.1103/PhysRevLett.132.035201

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Other Link： https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.132.035201

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Space Weather  

Geomagnetic storm effects on the LEO proton flux during solar energetic particle eventsGeomagnetic storm effects on the LEO proton flux during solar energetic particle events

DOI： 10.1029/2023SW003664

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Other Link： https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023SW003664

Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Astronomical Society  

Abstract

Magnetic reconnection is an important source of energetic particles in systems ranging from astrophysics to the laboratory. The large separation of spatiotemporal scales involved makes it critical to determine the minimum physical model containing the necessary physics for modeling particle acceleration. By resolving the energy gain from ideal and nonideal magnetohydrodynamic electric fields self-consistently in kinetic particle-in-cell simulations of reconnection, we conclusively show the dominant role of the nonideal field for the early stage of energization known as injection. The importance of the nonideal field increases with magnetization, guide field, and in three dimensions, indicating its general importance for reconnection in natural astrophysical systems. We obtain the statistical properties of the injection process from the simulations, paving the way for the development of extended MHD models capable of accurately modeling particle acceleration in large-scale systems. The novel analysis method developed in this study can be applied broadly to give new insight into a wide range of processes in plasma physics.

DOI： 10.3847/2041-8213/acdb60

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Other Link： https://iopscience.iop.org/article/10.3847/2041-8213/acdb60

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Astrophysical Journal  

Counterpropagating Alfvén waves are ubiquitously observed in many astrophysical environments, such as a star surface and a planetary foreshock. We discuss an efficient particle acceleration mechanism in two counterpropagating circularly polarized Alfvén waves. Phase transitions of particle behavior occur when wave amplitudes exceed two critical values. Above the critical amplitudes, the numerical simulation shows that any particles irreversibly gain relativistic energy within a short time regardless of their initial position and energy once the coherent waveform is formed. The accelerated particles have spatial coherence. Higher wave phase velocity requires smaller critical amplitudes, while the maximum attainable energy increases as the wavenumber and the frequency decrease. The results may be applicable in some astrophysical phenomena, as well as a future laboratory experiment using high-power lasers.

DOI： 10.3847/1538-4357/acbb6d

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Other Link： https://iopscience.iop.org/article/10.3847/1538-4357/acbb6d

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We theoretically and numerically investigate the ion-acoustic features of collective Thomson scattering (CTS) in two-stream plasmas. When the electron distribution functions of two (stationary and moving) components overlap with each other at the phase velocities corresponding to the two resonant peaks of the ion-acoustic feature, the theoretical spectrum shows asymmetry because the rate of electron Landau damping is different for the two peaks. The results of numerical simulations agree well with the theoretical spectra. We also demonstrate the effect of a two-stream-type instability in the ion-acoustic feature. The simulated spectrum in the presence of the instability shows an asymmetry with the opposite trend to the overlapped case, which results from the temporal change of the electron distribution function caused by the instability. Our results show that two-stream plasmas have significant effects on CTS spectra and that the waves resulting from instabilities can be observed in the ion-acoustic feature.

DOI： 10.1063/5.0117812

Other Link： https://aip.scitation.org/doi/10.1063/5.0117812

Language：English   Publishing type：Research paper (scientific journal)  

Ion-acoustic feature of collective Thomson scattering in non-equilibrium two-stream plasmas

DOI： 10.1063/5.0117812

Other Link： https://pubs.aip.org/aip/pop/article/30/1/012105/2867580/Ion-acoustic-feature-of-collective-Thomson

Language：Others   Publishing type：Research paper (scientific journal)   Publisher：American Physical Society (APS)  

Magnetic reconnection in laser-produced magnetized plasma is investigated by using optical diagnostics. The magnetic field is generated via the Biermann battery effect, and the inversely directed magnetic field lines interact with each other. It is shown by self-emission measurement that two colliding plasmas stagnate on a midplane, forming two planar dense regions, and that they interact later in time. Laser Thomson scattering spectra are distorted in the direction of the self-generated magnetic field, indicating asymmetric ion velocity distribution and plasma acceleration. In addition, the spectra perpendicular to the magnetic field show different peak intensity, suggesting an electron current formation. These results are interpreted as magnetic field dissipation, reconnection, and outflow acceleration. Two-directional laser Thomson scattering is, as discussed here, a powerful tool for the investigation of microphysics in the reconnection region.

DOI： 10.1103/physreve.106.055207

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Other Link： https://journals.aps.org/pre/abstract/10.1103/PhysRevE.106.055207

Language：English  

Other Link： https://www.actaphys.uj.edu.pl/index_n.php?I=S&V=15&N=3

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s41614-022-00093-1

Language：English   Publishing type：Research paper (scientific journal)  

Nonthermal electron acceleration at collisionless quasi-perpendicular shocks

DOI： 10.1007/s41614-022-00093-1

Other Link： https://link.springer.com/article/10.1007/s41614-022-00093-1

Language：English  

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DOI： 10.1103/physreve.106.025205

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

Abstract

Magnetic reconnection is a universal process in space, astrophysical, and laboratory plasmas. It alters magnetic field topology and results in energy release to the plasma. Here we report the experimental results of a pure electron outflow in magnetic reconnection, which is not accompanied with ion flows. By controlling an applied magnetic field in a laser produced plasma, we have constructed an experiment that magnetizes the electrons but not the ions. This allows us to isolate the electron dynamics from the ions. Collective Thomson scattering measurements reveal the electron Alfvénic outflow without ion outflow. The resultant plasmoid and whistler waves are observed with the magnetic induction probe measurements. We observe the unique features of electron-scale magnetic reconnection simultaneously in laser produced plasmas, including global structures, local plasma parameters, magnetic field, and waves.

DOI： 10.1038/s41598-022-14582-3

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Other Link： https://www.nature.com/articles/s41598-022-14582-3

Language：English   Publishing type：Research paper (scientific journal)  

We have studied the radiation environment of LEO spacecraft when passing through the South Atlantic Anomaly (SAA) during the geomagnetic storm event of 15 May 2005. The 70-180 MeV proton flux information were numerically obtained from a simulation model of the inner radiation belt. The radiation analysis was consisted of two parts: the estimation of the Single Event Upset (SEU) rates and the absorbed radiation doses. One of the characteristics of the SAA at 800 km altitude during the recovery phase of the geomagnetic storm was the enhancement of its southern proton flux cell. It was found that the excess SEU rates and absorbed radiation doses could reach at least 200 % and 70 % respectively during the recovery phase in comparison to the initial phase of the geomagnetic storm. The estimated radiation results were in a good agreement with observations.

DOI： 10.1109/JRFID.2022.3163441

Language：English   Publishing type：Research paper (scientific journal)  

Radiation Analysis of LEO Mission in the South Atlantic Anomaly During Geomagnetic Storm

DOI： 10.1109/JRFID.2022.3163441

Other Link： https://ieeexplore.ieee.org/document/9747924

Publisher：Proceedings of Science  

We study synchrotron maser emission and associated particle acceleration at electron-ion relativistic shocks by PIC simulations. Relativistic shocks emit intense electromagnetic waves from the shock front via the synchrotron maser instability. This synchrotron maser emission induces electrostatic plasma waves (i.e., wakefield) and transverse filamentary structures in the upstream region via the stimulated/induced Raman scattering and filamentation instability, respectively. Some lucky particles in the phase of the deceleration by the wakefield enter the filamentary structures. Then they are reflected by the wakefield and decoupled from the upstream bulk flow. These decoupled particles can feel the motional electric field and efficiently accelerated.

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Publisher：Proceedings of Science  

Energetic, non-thermal electrons with power-law energy spectra are directly observed in the vicinity of the Earth's quasi-perpendicular bow shock. However, the acceleration mechanism of these electrons remains unclear. Here we show, using 1D PIC simulations of a quasi-perpendicular collisionless shock (MA~7.1, shock angle 70°, beta ~0.3), that bursts of energetic electrons are produced at a reforming magnetic overshoot by betatron acceleration in addition to the shock drift acceleration. The betatron acceleration occurs through efficient trapping in a thin magnetic trough formed by a phase-standing whistler wave, and achieves an energy gain larger than that obtained by the shock drift acceleration only. We also found that the shock potential works against the acceleration, but the accelerations are more efficient and leads to the net energy gain. We envision that this betatron acceleration process is an important component of the entire process of electron acceleration to non-thermal energies at a non-stationary, quasi-perpendicular shock.

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Publisher：Proceedings of Science  

Radio and X-ray observations of radio relics indicate acceleration of relativistic electrons at merger shocks in galaxy clusters. These large-scale shocks can also be sites of ultra-high-energy cosmic ray production. It is assumed that diffusive shock acceleration (DSA) produces synchrotron-radiating electrons but the process of electron pre-acceleration from thermal to supra-thermal energies is poorly known. Using large-scale fully-kinetic two-dimensional particle-in-cell (PIC) simulations of a quasi-perpendicular subluminal shock with low sonic Mach number (Ms = 3) and propagating in hot intracluster medium with plasma beta β = 5 we have recently demonstrated that the main electron pre-acceleration mechanism is stochastic shock-drift acceleration (SSDA). In this process electrons are confined at the shock by pitch-angle scattering off turbulence and gain energy while drifting along the motional electric field. We showed that multi-scale magnetic turbulence, including ion-scale shock rippling modes, is essential for electron energization. This turbulence is driven by effective ion and electron temperature anisotropies in the entire shock transition. Wide-energy non-thermal electron distributions are formed both upstream and downstream of the shock and the maximum energy of the electrons is sufficient for their injection into DSA. Here we report on our new PIC simulation studies of SSDA process in a range of plasma beta (β = 5 − 30) and subluminal shock obliquity angles. We show that SSDA persists in facilitating the electron injection in rippled shocks. We also present how the SSDA efficiency vary with intracluster medium and shock parameters.

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Language：English  

Other Link： https://pos.sissa.it/cgi-bin/reader/conf.cgi?confid=395

Language：English  

Other Link： https://pos.sissa.it/cgi-bin/reader/conf.cgi?confid=395

Language：English  

Other Link： https://pos.sissa.it/cgi-bin/reader/conf.cgi?confid=395

Language：English  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

In order to estimate the proton flux variations occurring in the South Atlantic Anomaly (SAA) caused by the geodipole tilting angle and the Dst index variations, we performed three dimensional relativistic test particle simulations to calculate the trajectories of high-energy protons (70–180 MeV), where the static background magnetic field was calculated by the Tsyganenko models T01/TS05 combined with IGRF-12. As various parameters characterize the SAA proton flux, the study considered the maximum proton flux and the area of the SAA. Among many different parameters that define the space weather conditions, we considered the geodipole tilting angle and the Dst index. The numerical results showed that (1) the proton flux intensity was increased in the SAA for small geodipole tilting angles, which was confirmed by observations, and that (2) the proton flux intensity was also increased for significantly low Dst index.

DOI： 10.1016/j.jastp.2021.105808

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Other Link： https://www.sciencedirect.com/science/article/pii/S1364682621002583?via%3Dihub

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1103/physreve.105.025203

Language：English   Publishing type：Research paper (scientific journal)  

High-power laser experiment forming a supercritical collisionless shock in a magnetized uniform plasma at rest

DOI： 10.1103/PhysRevE.105.025203

Other Link： https://journals.aps.org/pre/abstract/10.1103/PhysRevE.105.025203

Language：English   Publishing type：Research paper (scientific journal)  

Particle acceleration by pickup process upstream of relativistic shocks

DOI： 10.3847/1538-4357/ac38aa

Other Link： https://iopscience.iop.org/article/10.3847/1538-4357/ac38aa

Language：Others   Publishing type：Research paper (scientific journal)  

<title>Abstract</title>
Particle acceleration at magnetized purely perpendicular relativistic shocks in electron–ion plasmas is studied by means of two-dimensional particle-in-cell simulations. Magnetized shocks with the upstream bulk Lorentz factor <italic>γ</italic>
₁ ≫ 1 are known to emit intense electromagnetic waves from the shock front, which induce electrostatic plasma waves (wakefield) and transverse filamentary structures in the upstream region via stimulated/induced Raman scattering and filamentation instability, respectively. The wakefield and filaments inject a fraction of the incoming particles into a particle acceleration process, in which particles are once decoupled from the upstream bulk flow by the wakefield, and are picked up again by the flow. The picked-up particles are accelerated by the motional electric field. The maximum attainable Lorentz factor is estimated as <inline-formula>
<tex-math>
<?CDATA &#36;{gamma }_{max ,e}sim alpha {gamma }_{1}^{3}&#36;?>
</tex-math>
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<mml:msub>
<mml:mrow>
<mml:mi>γ</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:mi>max</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>e</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>∼</mml:mo>
<mml:mi>α</mml:mi>
<mml:msubsup>
<mml:mrow>
<mml:mi>γ</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:mn>1</mml:mn>
</mml:mrow>
<mml:mrow>
<mml:mn>3</mml:mn>
</mml:mrow>
</mml:msubsup>
</mml:math>
<inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac38aaieqn1.gif" xlink:type="simple" />
</inline-formula> for electrons and <inline-formula>
<tex-math>
<?CDATA &#36;{gamma }_{max ,i}sim (1+{m}_{e}{gamma }_{1}/{m}_{i}){gamma }_{1}^{2}&#36;?>
</tex-math>
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<mml:msub>
<mml:mrow>
<mml:mi>γ</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:mi>max</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>i</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>∼</mml:mo>
<mml:mo stretchy="false">(</mml:mo>
<mml:mn>1</mml:mn>
<mml:mo>+</mml:mo>
<mml:msub>
<mml:mrow>
<mml:mi>m</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:mi>e</mml:mi>
</mml:mrow>
</mml:msub>
<mml:msub>
<mml:mrow>
<mml:mi>γ</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:mn>1</mml:mn>
</mml:mrow>
</mml:msub>
<mml:mrow>
<mml:mo stretchy="true">/</mml:mo>
</mml:mrow>
<mml:msub>
<mml:mrow>
<mml:mi>m</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:mi>i</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo stretchy="false">)</mml:mo>
<mml:msubsup>
<mml:mrow>
<mml:mi>γ</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:mn>1</mml:mn>
</mml:mrow>
<mml:mrow>
<mml:mn>2</mml:mn>
</mml:mrow>
</mml:msubsup>
</mml:math>
<inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac38aaieqn2.gif" xlink:type="simple" />
</inline-formula> for ions, where <italic>α</italic> ∼ 10 is determined from our simulation results. <italic>α</italic> can increase up to <italic>γ</italic>
₁ for a weakly magnetized shock if <italic>γ</italic>
₁ is sufficiently large. This result indicates that highly relativistic astrophysical shocks such as external shocks of gamma-ray bursts can be an efficient particle accelerator.

DOI： 10.3847/1538-4357/ac38aa

Publisher：Acta Physica Polonica B, Proceedings Supplement  

The statistics of galactic cosmic rays (GCRs) invading the heliosphere are investigated using numerical simulations. First, a time stationary global heliosphere is reproduced using an MHD simulation. Then, motions of a large number of GCR protons with initial Lorentz factor 10 (∼ 10 GeV) and 1000 (∼ 1 TeV), distributed in the interstellar space around the heliosphere, are numerically solved. We map the positional distribution of the GCRs arriving at 50 AU from the Sun. Our results show that the arrival position of GCRs depends on their energies. We discuss the statistical behavior of the arriving GCRs at each energy.

DOI： 10.5506/APhysPolBSupp.15.3-A20

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Language：Others   Publishing type：Research paper (other academic)  

DOI： 10.1109/wisee50203.2021.9613828

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.3847/1538-4357/ac1107

Language：English   Publishing type：Research paper (scientific journal)  

Inner radiation belt simulations of the proton flux response in the South Atlantic Anomaly during the Geomagnetic Storm of 15 May 2005

DOI： 10.1051/swsc/2021031

Other Link： https://www.swsc-journal.org/articles/swsc/full_html/2021/01/swsc210016/swsc210016.html

Language：Others   Publishing type：Research paper (scientific journal)  

A test particle simulation code was developed to simulate the inner proton belt response during the intense geomagnetic storm of 15 May 2005. The guiding center model was implemented to compute the proton trajectories with an energy range of 70–180 MeV. The time-varying magnetic field model implemented in the simulations was computed by the Tsyganenko model TS05 with the associated inductive electric field. One of the most important features of the low-earth orbit (LEO) environment is the South Atlantic Anomaly, which imposes a dangerous radiation load on most LEO missions. This research aims to investigate the proton flux variations in the anomaly region with respect to space weather conditions. The results showed that during the main phase of the geomagnetic storm, the proton flux in the SAA decreased, whereas, throughout the initial and recovery phases, the proton flux was increased at most of the altitudes. Satellite measurements confirmed numerical results.

DOI： 10.1051/swsc/2021031

Language：Others   Publishing type：Research paper (other academic)  

DOI： 10.1109/icops36761.2021.9588519

Language：English   Publishing type：Research paper (scientific journal)  

Electron Acceleration at Rippled Low-mach-number Shocks in High-beta Collisionless Cosmic Plasmas

DOI： 10.3847/1538-4357/ac1107

Other Link： https://iopscience.iop.org/article/10.3847/1538-4357/ac1107

Language：English  

DOI： 10.3847/1538-4357/ac02c2

Other Link： https://iopscience.iop.org/article/10.3847/1538-4357/ac02c2

Language：English   Publishing type：Research paper (scientific journal)  

Mildly relativistic magnetized shocks in electron-ion plasmas - I. Electromagnetic shock structure

DOI： 10.1093/mnras/staa3901

Other Link： https://academic.oup.com/mnras/article/501/4/4837/6043236

Language：Others   Publishing type：Research paper (scientific journal)  

<title>ABSTRACT</title>
Mildly relativistic shocks in magnetized electron–ion plasmas are investigated with 2D kinetic particle-in-cell simulations of unprecedentedly high resolution and large scale for conditions that may be found at internal shocks in blazar cores. Ion-scale effects cause corrugations along the shock surface whose properties somewhat depend on the configuration of the mean perpendicular magnetic field, that is either in or out of the simulation plane. We show that the synchrotron maser instability persists to operate in mildly relativistic shocks in agreement with theoretical predictions and produces coherent emission of upstream-propagating electromagnetic waves. Shock front ripples are excited in both mean-field configurations and they engender effective wave amplification. The interaction of these waves with upstream plasma generates electrostatic wakefields.

DOI： 10.1093/mnras/staa3901

Language：Others   Publishing type：Research paper (scientific journal)  

<title>Abstract</title>
Particle acceleration and heating at mildly relativistic magnetized shocks in electron-ion plasma are investigated with unprecedentedly high-resolution two-dimensional particle-in-cell simulations that include ion-scale shock rippling. Electrons are super-adiabatically heated at the shock, and most of the energy transfer from protons to electrons takes place at or downstream of the shock. We are the first to demonstrate that shock rippling is crucial for the energization of electrons at the shock. They remain well below equipartition with the protons. The downstream electron spectra are approximately thermal with a limited supra-thermal power-law component. Our results are discussed in the context of wakefield acceleration and the modelling of electromagnetic radiation from blazar cores.

DOI： 10.1093/mnras/stab220

Language：English   Publishing type：Research paper (scientific journal)  

Mildly relativistic magnetized shocks in electron-ion plasmas - II. Particle acceleration and heating

DOI： 10.1093/mnras/stab220

Other Link： https://academic.oup.com/mnras/article/502/4/5065/6122574

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1186/s40623-020-01221-2

Language：English   Publishing type：Research paper (scientific journal)  

Collective Thomson scattering in non-equilibrium laser produced two-stream plasmas

DOI： 10.1063/5.0011935

Other Link： https://aip.scitation.org/doi/10.1063/5.0011935

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1063/5.0011935

Language：English   Publishing type：Research paper (scientific journal)  

PIC simulations of microinstabilities and waves at near-sun solar wind perpendicular shocks: Predictions for Parker Solar Probe and Solar Orbiter

DOI： 10.3847/2041-8213/abaf59

Other Link： https://iopscience.iop.org/article/10.3847/2041-8213/abaf59

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1088/1742-6596/1620/1/012013

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.3847/2041-8213/abaf59

Language：English   Publishing type：Research paper (scientific journal)  

Local plasma parameter measurements in colliding laser-produced plasmas for studying magnetic reconnection

DOI： 10.1016/j.hedp.2020.100754

Other Link： https://www.sciencedirect.com/science/article/pii/S157418182030032X?via%3Dihub

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.hedp.2020.100754

Language：English   Publishing type：Research paper (scientific journal)  

Solar wind parameter and seasonal variation effects on the south atlantic anomaly using Tsyganenko models

DOI： 10.1186/s40623-021-01367-7

Other Link： https://earth-planets-space.springeropen.com/articles/10.1186/s40623-020-01221-2

Language：Others  

<p>In this study, we assess the hourly variations of the three-dimensional proton flux distribution inside the South Atlantic Anomaly (SAA) during a geomagnetic storm. We have developed a relativistic three-dimensional guiding center test particle simulation code in order to compute the proton trajectories in a time-varying magnetic field background provided by Tsyganenko model TS05 and the corresponding time-varying inductive electric field. The Dst index is the main input parameter to the simulation model, while the maximum proton flux, the area of the SAA calculated below a selected threshold, and the penetration depth of the protons are the main output variables investigated in this study were. Since the LEO spacecraft and human-related activities are already affected by space weather conditions, the South Atlantic Anomaly (SAA) is also believed to create an additional source of risk. As the radiation environment depends essentially on the particle flux, the objective of this study is to estimate quantitatively the proton flux variations inside the South Atlantic Anomaly (SAA) in quiet and in storm conditions. So far, it was found that after several drift periods, the protons in the South Atlantic Anomaly (SAA) could penetrate to lower altitudes during geomagnetic storm event, and that, the SAA maximum flux value and the corresponding area, varied differently with respect to altitudes. Numerical results were compared with observations by NOAA 17 and RD3R2 instrument mounted on International Space Station (ISS).</p>

DOI： 10.5194/egusphere-egu2020-1551

Language：English   Publishing type：Research paper (scientific journal)  

Mach number and plasma beta dependence of the ion temperature perpendicular to the external magnetic field in the transition region of perpendicular collisionless shocks

DOI： 10.1063/1.5129067

Other Link： https://aip.scitation.org/doi/10.1063/1.5129067

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.3847/1538-4357/ab54c9

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1063/1.5129067

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.3847/2041-8213/ab58cf

Language：English   Publishing type：Research paper (scientific journal)  

Electrons are accelerated to nonthermal energies at shocks in space and astrophysical environments. While shock drift acceleration (SDA) has been considered a key process of electron acceleration at Earth’s bow shock, it has also been recognized that SDA needs to be combined with an additional stochastic process to explain the observed power-law energy spectra. Here, we show mildly energetic (∼0.5 keV) electrons are locally scattered (and accelerated while being confined) by magnetosonic-whistler waves within the shock transition layer, especially when the shock angle is large ({θ }Bn}≳ 70^\circ ). When measured by the Magnetospheric Multiscale mission at a high cadence, ∼0.5 keV electron flux increased exponentially in the shock transition layer. However, the flux profile was not entirely smooth and the fluctuation showed temporal/spectral association with large-amplitude (δ B/B∼ 0.3), low-frequency (≲ 0.1{{{Ω }}}ce} where {{{Ω }}}ce} is the cyclotron frequency), obliquely propagating ({θ }kB}∼ 30^\circ {--}60^\circ , where {θ }kB} is the angle between the wave vector and background magnetic field) whistler waves, indicating that the particles were interacting with the waves. Particle simulations demonstrate that, although linear cyclotron resonances with ∼0.5 keV electrons are unlikely due to the obliquity and low frequencies of the waves, the electrons are still scattered beyond 90° pitch angle by (1) resonant mirroring (transit-time damping), (2) non-resonant mirroring, and (3) subharmonic cyclotron resonances. Such coupled nonlinear scattering processes are likely to provide the stochasticity needed to explain the power-law formation.

DOI： 10.3847/1538-4357/ab4a81

Other Link： https://iopscience.iop.org/article/10.3847/1538-4357/ab4a81

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.hedp.2019.100709

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.3847/1538-4357/ab4a81

Language：English   Publishing type：Research paper (scientific journal)  

PIC Simulation of a quasi-parallel collisionless shock: Interaction between upstream waves and backstreaming ions

DOI： 10.1016/j.hedp.2019.100709

Other Link： https://www.sciencedirect.com/science/article/pii/S1574181818300867?via%3Dihub

Language：English   Publishing type：Research paper (scientific journal)  

Anomalous plasma acceleration in colliding high-power laser-produced plasmas

DOI： 10.1063/1.5100197

Language：English   Publishing type：Research paper (scientific journal)  

We developed an experimental platform for studying magnetic reconnection in an external magnetic field with simultaneous measurements of plasma imaging, flow velocity, and magnetic-field variation. Here, we investigate the stagnation and acceleration in counterstreaming plasmas generated by high-power laser beams. A plasma flow perpendicular to the initial flow directions is measured by laser Thomson scattering. The flow is, interestingly, accelerated toward the high-density region, which is opposite to the direction of the acceleration by pressure gradients. This acceleration is possibly interpreted by the interaction of two magnetic field loops initially generated by the Biermann battery effect, resulting in a magnetic reconnection forming a single field loop and additional acceleration by a magnetic tension force.

DOI： 10.1063/1.5100197

Other Link： https://aip.scitation.org/doi/10.1063/1.5100197

Language：English   Publishing type：Research paper (scientific journal)  

Collective Thomson scattering (CTS) has been applied to laser-produced plasmas with Gekko XII HIPER laser facility. A scheme of stimulated Brillouin scattering (SBS) has been used in CTS measurements for the first time. Utilizing SBS shortens the probe pulse, which increases the scattered power, and thus collected scattered signal of CTS. Therefore, a lower energy probe laser can be used for given background emission levels to avoid probe heating, which is crucial for plasmas with low electron temperature. Both electron and ion features of CTS have been successfully detected by using the SBS technique. The spatial profile of electron density, temperature, and drift velocity have been estimated in an ablation plasma. In addition to the local measurements with CTS, a global structure of plasmas has been obtained with optical imaging of the self-emission of plasmas and the interferometry. In the aspects of drift velocity and plasma density, the local and global information are in good agreement.

DOI： 10.1016/j.hedp.2019.06.002

Other Link： https://www.sciencedirect.com/science/article/pii/S1574181818301058?via%3Dihub

Language：Others   Publishing type：Research paper (scientific journal)  

Collective Thomson scattering measurements of electron feature using stimulated Brillouin scattering in laser-produced plasmas
© 2019 Collective Thomson scattering (CTS) has been applied to laser-produced plasmas with Gekko XII HIPER laser facility. A scheme of stimulated Brillouin scattering (SBS) has been used in CTS measurements for the first time. Utilizing SBS shortens the probe pulse, which increases the scattered power, and thus collected scattered signal of CTS. Therefore, a lower energy probe laser can be used for given background emission levels to avoid probe heating, which is crucial for plasmas with low electron temperature. Both electron and ion features of CTS have been successfully detected by using the SBS technique. The spatial profile of electron density, temperature, and drift velocity have been estimated in an ablation plasma. In addition to the local measurements with CTS, a global structure of plasmas has been obtained with optical imaging of the self-emission of plasmas and the interferometry. In the aspects of drift velocity and plasma density, the local and global information are in good agreement.

DOI： 10.1016/j.hedp.2019.06.002

Language：English  

Other Link： https://pos.sissa.it/358/368/

Language：English   Publishing type：Research paper (scientific journal)  

A preliminary numerical experiment is conducted for laboratory experiments on the generation of magnetized collisionless shocks with high-power lasers by using one-dimensional particle-in-cell simulation. The present study deals with the interaction between a moving aluminum plasma and a nitrogen plasma at rest. In the numerical experiment, the nitrogen plasma is unmagnetized or magnetized by a weak external magnetic field. Since the previous study suggested the generation of a spontaneous magnetic field in the piston (aluminum) plasma due to the Biermann battery, the effect of the magnetic field is of interest. Sharp jumps of the electron density and magnetic field are observed around the interface between the two plasmas as long as one of the two plasmas is magnetized, which indicates the formation of tangential electron-magneto-hydro-dynamic discontinuity. When the aluminum plasma is magnetized, strong compression of both the density and the magnetic field takes place in the pure aluminum plasma during the gyration of nitrogen ions in the aluminum plasma region. The formation of a shock downstream is obtained from the shock jump condition. The results suggest that the spontaneous magnetic field in the piston (aluminum) plasma plays an essential role in the formation of a perpendicular collisionless shock.

DOI： 10.1063/1.5079906

Other Link： https://aip.scitation.org/doi/10.1063/1.5079906

Language：English   Publishing type：Research paper (scientific journal)  

Full particle-in-cell simulation of the interaction between two plasmas for laboratory experiments on the generation of magnetized collisionless shocks with high-power lasers
A preliminary numerical experiment is conducted for laboratory experiments on the generation of magnetized collisionless shocks with high-power lasers by using one-dimensional particle-in-cell simulation. The present study deals with the interaction between a moving aluminum plasma and a nitrogen plasma at rest. In the numerical experiment, the nitrogen plasma is unmagnetized or magnetized by a weak external magnetic field. Since the previous study suggested the generation of a spontaneous magnetic field in the piston (aluminum) plasma due to the Biermann battery, the effect of the magnetic field is of interest. Sharp jumps of the electron density and magnetic field are observed around the interface between the two plasmas as long as one of the two plasmas is magnetized, which indicates the formation of tangential electron-magneto-hydro-dynamic discontinuity. When the aluminum plasma is magnetized, strong compression of both the density and the magnetic field takes place in the pure aluminum plasma during the gyration of nitrogen ions in the aluminum plasma region. The formation of a shock downstream is obtained from the shock jump condition. The results suggest that the spontaneous magnetic field in the piston (aluminum) plasma plays an essential role in the formation of a perpendicular collisionless shock. Published under license by AIP Publishing.

DOI： 10.1063/1.5079906

Language：English   Publishing type：Research paper (scientific journal)  

Magnetic reconnections play essential roles in space, astrophysical, and laboratory plasmas, where the anti-parallel magnetic field components re-connect and the magnetic energy is converted to the plasma energy as Alfvénic out flows. Although the electron dynamics is considered to be essential, it is highly challenging to observe electron scale reconnections. Here we show the experimental results on an electron scale reconnection driven by the electron dynamics in laser-produced plasmas. We apply a weak-external magnetic field in the direction perpendicular to the plasma propagation, where the magnetic field is directly coupled with only the electrons but not for the ions. Since the kinetic pressure of plasma is much larger than the magnetic pressure, the magnetic field is distorted and locally anti-parallel. We observe plasma collimations, cusp and plasmoid like features with optical diagnostics. The plasmoid propagates at the electron Alfvén velocity, indicating a reconnection driven by the electron dynamics.

DOI： 10.1038/s41467-018-07415-3

Other Link： https://www.nature.com/articles/s41467-018-07415-3

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1038/S41467-018-07415-3

Language：English  

This study reports observations of energetic ions upstream of the Earth’s quasi-parallel bow shock by Cluster at times when interspacecraft separation distances were large. We analyze two individual upstream ion events during high solar wind velocity conditions to compare the spatial evolution of partial energetic ion densities in front of the Earth’s bow shock along the magnetic field line. Using a bow shock model, we determine the distance of SC1 and SC3 to the bow shock surface parallel to the magnetic field. The CIS-HIA instrument on board Cluster provides partial energetic ion densities in four energy channels between 10 and 32 keV. Using the differences of the partial energetic ion densities observed on SC1 and SC3, and the distances of the spacecraft to the bow shock, we determine the spatial gradient of partial energetic ion densities at various distances from the bow shock. We show, for the first time, that the e-folding distance and the diffusion coefficient of the diffuse ions become unusually small when these ions interact with high-intensity waves generated by a strong field-aligned beam.

DOI： 10.3847/1538-4357/aad08c

Other Link： https://iopscience.iop.org/article/10.3847/1538-4357/aad08c

Language：English  

The Earth’s foreshock extends to a large domain of upstream quasi-parallel bow shock, and is
characterized by a presence of field-aligned beams (FABs), diffuse ions, ultra-low frequency
(ULF) waves, high frequency whistler waves, shocklets, and so on. Kinetic self-consistent numerical simulation is one of the key tools to analyze detailed physics of the foreshock which
has not been clearly understood. Because of the necessity of the large simulation domain, a full
particle-in-cell (PIC) simulation of quasi-parallel shock has seldom been performed. In this paper
we show preliminary results of a long-term and large-scale one-dimensional full PIC simulation
of the quasi-parallel collisionless shock with the Alfvén Mach number 6.6 and shock angle 20
degrees. The FAB component is observed far upstream with the beam velocity of 10.5 times the
Alfvén velocity and the beam density of 0.5 &#37; of the background plasma. This FAB generates
right-handed Alfvén waves in the plasma rest frame via resonant mode instability, and the excited waves are amplified as approaching the shock during the plasma convection. The number
densities of energetic particles for both electrons and ions also increase as approaching the shock.

DOI： 10.22323/1.301.0078

Other Link： https://pos.sissa.it/301/078/

Language：English  

Diffusive shock acceleration (Fermi acceleration) of cosmic rays in a system containing two shock waves is investigated using test particle simulations and analysis of the diffusion convection equation. We assume that the cosmic ray acceleration timescale is much less than the approaching timescale of the two shocks. Low-energy cosmic rays are primarily accelerated as they interact with one of the two shocks. However, as they are energized, and their mean free path becomes comparable to the separation distance of the two shocks, they start to accelerate as they interact with both shocks. As a result, a double power-law-type spectrum for the cosmic ray distribution is produced. The numerical result is well explained by a model based on the diffusion convection equation, which accounts for the dependence of the diffusion coefficient on the cosmic ray energy. The break point of the spectrum can be estimated by considering transport of cosmic rays from one shock to the other.

DOI： 10.1186/s40623-018-0799-3

Other Link： https://earth-planets-space.springeropen.com/articles/10.1186/s40623-018-0799-3

Language：English   Publishing type：Research paper (scientific journal)  

Effect of upstream ULF waves on the energetic ion fiffusion at the Earth's foreshock: I. Theory and simulation

DOI： 10.3847/1538-4357/aa8363

Other Link： http://iopscience.iop.org/article/10.3847/1538-4357/aaa23f/meta

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.3847/1538-4357/aaa23f

Language：English   Publishing type：Research paper (scientific journal)  

Electromagnetic structure and electron acceleration in shock-shock interaction

DOI： 10.3847/1538-4357/aa8363

Other Link： http://iopscience.iop.org/article/10.3847/1538-4357/aa8363/meta

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.3847/1538-4357/aa8363

Language：English   Publishing type：Research paper (scientific journal)  

Spatial and temporal plasma evolutions of magnetic reconnection in laser produced plasmas

DOI： 10.1016/j.hedp.2017.02.004

Other Link： https://www.sciencedirect.com/science/article/pii/S1574181817300095?via%3Dihub

Language：English   Publishing type：Research paper (scientific journal)  

Time evolution of Kelvin-Helmholtz vortices associated with collisionless shocks in laser-produced plasmas

DOI： 10.3847/0004-637X/828/2/93

Other Link： http://iopscience.iop.org/article/10.3847/0004-637X/828/2/93/meta

Language：English   Publishing type：Research paper (scientific journal)  

We report experimental results on Kelvin-Helmholtz (KH) instability and resultant vortices in laser-produced plasmas. By irradiating a double plane target with a laser beam, asymmetric counterstreaming plasmas are created. The interaction of the plasmas with different velocities and densities results in the formation of asymmetric shocks, where the shear flow exists along the contact surface and the KH instability is excited. We observe the spatial and temporal evolution of plasmas and shocks with time-resolved diagnostics over several shots. Our results clearly show the evolution of transverse fluctuations, wavelike structures, and circular features, which are interpreted as the KH instability and resultant vortices. The relevant numerical simulations demonstrate the time evolution of KH vortices and show qualitative agreement with experimental results. Shocks, and thus the contact surfaces, are ubiquitous in the universe; our experimental results show general consequences where two plasmas interact.

DOI： 10.3847/0004-637X/828/2/93

Language：English  

Language：English  

Language：English   Publishing type：Research paper (international conference proceedings)  

Spherical shock in the presence of an external magnetic field

DOI： 10.1088/1742-6596/688/1/012056

Other Link： http://iopscience.iop.org/article/10.1088/1742-6596/688/1/012056

Language：English   Publishing type：Research paper (scientific journal)  

Toward the Generation of Magnetized Collisionless Shocks with High-Power Lasers
<p>We have started a project of experimental generation of low Mach number collisionless shocks propagating into magnetized plasma, using high power lasers such as Gekko XII at Institute of laser engineering, Osaka University. We briefly present a result of our first experiments done in September 2014, in which Aluminum plane target was irradiated by main laser in ambient Helium gas with external magnetic field. Ejected Aluminum plasma had a bulk velocity of 430 km s⁻¹, which is sufficient enough to excite the magnetized collisionless shock in our experimental setup. However, the ejected Aluminum plasma was decelerated before the shock was excited.</p>

DOI： 10.1585/pfr.11.3401031

Language：English   Publishing type：Research paper (other academic)  

One of the important and interesting problems in astrophysics and plasma physics is collimation of plasma jets. The collimation mechanism, which causes a plasma flow to propagate a long distance, has not been understood in detail. We have been investigating a model experiment to simulate astrophysical plasma jets with an external magnetic field [Nishio et al., EPJ. Web of Conferences 59, 15005 (2013)]. The experiment was performed by using Gekko XII HIPER laser system at Institute of Laser Engineering, Osaka University. We shot CH plane targets (3 mm x 3 mm x 10 mu m) and observed rear-side plasma flows. A collimated plasma flow or plasma jet was generated by separating focal spots of laser beams. In this report, we measured plasma jet structure without an external magnetic field with shadowgraphy, and simultaneously measured the local parameters of the plasma jet, i.e., electron density, electron and ion temperatures, charge state, and drift velocity, with collective Thomson scattering.

DOI： 10.1088/1742-6596/688/1/012098

Language：English   Publishing type：Research paper (international conference proceedings)  

Toward the generation of magnetized collisionless shocks with high-power lasers

DOI： 10.1585/pfr.11.3401031

Other Link： http://www.jspf.or.jp/PFR/PFR_articles/pfr2016/pfr2016_11-3401031.html

Language：English   Publishing type：Research paper (international conference proceedings)  

Thomson scattering measurement of a collimated plasma jet generated by a high-power laser system

DOI： 10.1088/1742-6596/688/1/012098

Other Link： http://iopscience.iop.org/article/10.1088/1742-6596/688/1/012098

Language：English   Publishing type：Research paper (scientific journal)  

Model experiment of magnetic field amplification in laser-produced plasmas via the Richtmyer-Meshkov instability

DOI： https://doi.org/10.1063/1.4944925

Other Link： https://aip.scitation.org/doi/10.1063/1.4944925

Language：Others   Publishing type：Research paper (scientific journal)  

Model experiment of magnetic field amplification in laser-produced plasmas via the Richtmyer-Meshkov instability

DOI： 10.1063/1.4944925

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1088/1742-6596/688/1/012062

Language：Others  

Electron Acceleration at a High Beta and Low Mach Number Rippled Shock

DOI： 10.1088/1742-6596/642/1/012017

Language：English  

Language：English  

Language：English  

Language：English   Publishing type：Research paper (scientific journal)  

The microstructure of the heliospheric termination shock and the accompanied local acceleration processes of both ions and electrons are investigated by utilizing one-dimensional full particle-in-cell simulations for a variety of parameters. The relative pickup ion density is assumed to be 20-30&#37;. The magnetic field and the shock potential profiles exhibit significant differences, since the former mostly reflects the dynamics of solar wind ions, whereas the latter is mainly sustained by the bulk motion of the reflected pickup ions in the extended foot. The discrepancy between the magnetic field profile and the potential profile increases with Alfvén Mach number. Most of the downstream thermal energy is gained by the pickup ions, while some heating of the solar wind ions and electrons occurs through the modified two-stream instability excited in the extended foot. Self-reformation can occur when the relative pickup ion density is 20&#37; but is blurred when it becomes as large as 30&#37;. Reformation is also suppressed if the local solar wind ion temperature in the extended foot is high, which can either be due to heating by the modified two-stream instability or is already determined by the solar wind temperature far upstream. In all runs presented in this study no evidence for shock surfing acceleration of pickup ions could be found. Nonthermal particle acceleration occurs for oblique shocks. Electron (pickup ion) shock drift acceleration is evidenced when the shock angle is below 80° (60°). Key Points Parameter dependences of microstructures of the termination shock are examined Profiles of magnetic field and potential show significant differences Shock drift acceleration mechanism works for both electrons and pickup ions ©2014. American Geophysical Union. All Rights Reserved.

DOI： 10.1002/2013JA019654

Language：English  

DOI： 10.7566/JPSCP.1.015103

Other Link： http://journals.jps.jp/doi/abs/10.7566/JPSCP.1.015103

Language：English  

DOI： 10.1063/1.4863836

Other Link： http://scitation.aip.org/content/aip/journal/pop/21/2/10.1063/1.4863836

Language：English  

Language：English   Publishing type：Research paper (scientific journal)  

A one-dimensional full particle-in-cell (PIC) code is utilized to investigate energetic electron bursts produced at a nonstationary quasi-perpendicular shock. A number of electrons are intermittently energized by interacting with nonstationary electromagnetic fields in the shock front. Some of the energetic electrons are reflected at the shock and form an upstream non-thermal population. The reflection process is strongly affected by the non-coplanar magnetic field component which is temporarily rather strong in the transition region of a highly nonstationary shock. Oblique whistler waves in the transition region influence the distribution function of the reflected electrons. Waves excited by the modified two-stream instability may pitch angle scatter the electrons and thus blur the loss cone feature of the reflected electrons. Dispersive standing whistler waves are also emitted locally in the foot even when a Mach number exceeds a critical value. These whistler waves may also scatter the electrons to blur the loss cone. Furthermore, the whistler waves produce clumps of the reflected electrons in a phase space. Some electrons are trapped by the ion holes produced downstream as a remnant of a self-reformation process of the shock front and accelerated through a drift mechanism. It is also discussed how physical quantities associated with the reflected electrons observed upstream of the shock can give information about the shock front nonstationarity as well as about local small scale wave activities in the transition region. © 2012 American Geophysical Union. All Rights Reserved.

DOI： 10.1029/2012JA017986

Language：English  

DOI： 10.1063/1.4736848

Other Link： http://pop.aip.org/resource/1/phpaen/v19/i7/p072107_s1

Language：English  

DOI： 10.1063/1.3703319

Other Link： http://pop.aip.org/resource/1/phpaen/v19/i4/p042109_s1

Language：English  

DOI： 10.1007/s11214-012-9878-0

Other Link： http://www.springerlink.com/content/r4u5545437478w4h/?MUD=MP

Language：English  

DOI： 10.1029/2011JA017182

Other Link： http://www.agu.org/pubs/crossref/2012/2011JA017182.shtml

Language：English  

RELATIVISTIC ELECTRON SHOCK DRIFT ACCELERATION IN LOW MACH NUMBER GALAXY CLUSTER SHOCKS

DOI： 10.1088/0004-637X/742/1/47

Language：English   Publishing type：Research paper (scientific journal)  

A particle-in-cell code is used to examine kinetic properties of pickup ions at the heliospheric termination shock. The code treats the pickup ions self-consistently as a third component. The simulations are one-dimensional in spatial variations. We use a relative pickup ion density of 30&#37; and two different values of the magnetic field-shock normal angle: Bn = 90 and Bn = 87. The oblique shock is chosen in order to allow for wave vectors parallel to the magnetic field due to instabilities in the foot. In addition, a run is presented with a 60&#37; relative pickup ion density to investigate a pickup ion-dominated shock. Upstream of the ramp is an extended foot due to reflected pickup ions. In this foot the magnetic field continuously increases, and the bulk speed of the pickup ions as well as the bulk speed of the solar wind ions decrease and reach at the magnetic field ramp the downstream value. The positive bulk velocity of the pickup ions in the extended foot perpendicular to the magnetic field and to the shock normal causes an electric field in the shock normal direction. This leads to a large increase of the shock potential well upstream of the magnetic field ramp. The maximum value of the potential is ∼0.35 the shock ram energy and is by a factor 5 larger than expected for a weak shock without pickup ions. Pickup ion reflection at the shock is almost 100&#37;
part of the pickup ions are essentially specularly reflected by the magnetic field force term of the Lorentz force in the overshoot and part of the pickup ions are reflected in the extended foot due to a combination of the magnetic force term and the cross-shock potential. In the 30&#37; pickup ion case, about 90&#37; of the total thermal energy gain in the shock is gained by pickup ions, a little under 10&#37; by the solar wind ions. The thermal energy gain by pickup ions increases as the pickup ion relative density increases. The pickup ion temperature increases continuously from the upstream edge of the extended foot to the shock ramp and then stays constant through the overshoot and downstream. Copyright © 2011 by the American Geophysical Union.

DOI： 10.1029/2011JA016563

Language：English   Publishing type：Research paper (scientific journal)  

Non-stationarity of the quasi-perpendicular bow shock: comparison between Cluster observations and simulations

DOI： 10.5194/angeo-29-263-2011

Other Link： http://www.ann-geophys.net/29/263/2011/

Language：English   Publishing type：Research paper (scientific journal)  

We have performed full particle electromagnetic simulations of a quasi- perpendicular shock. The shock parameters have been chosen to be appropriate for the quasiperpendicular Earth's bow shock observed by Cluster on 24 January 2001 (Lobzin et al., 2007). We have performed two simulations with different ion to electron mass ratio: run 1 with m(i)/m(e) = 1840 and run 2 with m(i)/m(e) = 100. In run 1 the growth rate of the modified two- stream instability (MTSI) is large enough to get excited during the reflection and upstream gyration of part of the incident solar wind ions. The waves due to the MTSI are on the whistler mode branch and have downstream directed phase velocities in the shock frame. The Poynting flux (and wave group velocity) far upstream in the foot is also directed in the downstream direction. However, in the density and magnetic field compression region of the overshoot the waves are refracted and the Poynting flux in the shock frame is directed upstream. The MTSI is suppressed in the low mass ratio run 2. The low mass ratio run shows more clearly the non-stationarity of the shock with a larger time scale of the order of an inverse ion gyrofrequency (Omega(ci)): the magnetic field profile flattens and steepens with a period of similar to 1.5 Omega(-1)(ci). This non-stationarity is different from reformation seen in previous simulations of perpendicular or quasi-perpendicular shocks. Beginning with a sharp shock ramp the large electric field in the normal direction leads to high reflection rate of solar wind protons. As they propagate upstream, the ion bulk velocity decreases and the magnetic field increases in the foot, which results in a flattening of the magnetic field profile and in a decrease of the normal electric field. Subsequently the reflection rate decreases and the whole shock profile steepens again. Superimposed on this ' breathing' behavior are in the realistic mass ratio case the waves due to the MTSI. The simulations lead us to a re-interpretation of the 24 January 2001 bow shock observations reported by Lobzin et al. (2007). It is suggested that the high frequency waves observed in the magnetic field data are due to the MTSI and are not related to a nonlinear phase standing whistler. Different profiles at the different spacecraft are due to the non-stationary behavior on the larger time scale.

DOI： 10.5194/angeo-29-263-2011

Language：English  

DOI： 10.1029/2010JA015458

Other Link： http://www.agu.org/pubs/crossref/2010/2010JA015458.shtml

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1063/1.3372137

Language：Japanese  

Language：Japanese  

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1088/0004-637x/692/2/1004

Language：English   Publishing type：Research paper (scientific journal)  

Parametric instabilities of large-amplitude parallel propagating Alfvén waves: 2D PIC simulation

DOI： 10.1088/1367-2630/10/8/083004

Other Link： http://www.iop.org/EJ/abstract/1367-2630/10/8/083004/

Language：English   Publishing type：Research paper (international conference proceedings)  

Shock Modification by Cosmic-Ray-Excited Turbulences

Other Link： http://ptp.ipap.jp/link?PTPS/169/146/

Language：English   Publishing type：Research paper (scientific journal)  

Shock Modification by Cosmic-Ray-Excited Turbulences
In cosmic-ray-mediated shocks large amplitude Alfven waves are believed to be generated by accelerated cosmic ray particles. The enhanced magnetic pressure shared by these waves is non-negligible in the momentum and energy balances across the shock transition region. Accordingly the shock Rankine-Hugoniot condition is further modified, and the compression ratio across the shock departs from the classical values of 4 (nonrelativistic) and 7 (relativistic). We argue that in the 'grand equipartition' limit, namely equipartition among the waves, the background plasma, and the cosmic ray particles, the compression ratio recovers to the value of 4, and the corresponding spectral index of cosmic ray particles also comes back to the canonical value of 2.

DOI： 10.1143/ptps.169.146

Language：Japanese  

Language：English  

Language：Others   Publishing type：Research paper (scientific journal)  

Abstract. We have performed 3 one-dimensional full particle electromagnetic simulations of a quasi-perpendicular shock with the same Alfvén Mach number MA~5, shock normal-magnetic field angle ΘBn=87° and ion and electron beta (particle to magnetic field pressure) of 0.1. In the first run we used an ion to electron mass ratio close to the physical one (mi/me=1024). As expected from previous high mass ratio simulations the Modified Two-Stream instability develops in the foot of the shock, and the shock periodically reforms itself. We have then self-consistently included in the simulation 10% pickup protons distributed on a shell in velocity space as a third component. In a run with an unrealistically low mass ratios of 200 the shock still reforms itself; reformation is due to accumulation of specularly reflected particles at the upstream edge of the foot. In a third run including pickup protons we used a mass ratio of 1024. The shock reforms periodically as in the low mass ratio run with a somewhat smaller time constant. The specular reflection of pickup protons results in an increase of the shock potential some distance ahead of the shock foot and ramp. The minimum scale of the cross shock potential during reformation is about 7 electron inertial length λe. We do not find any pickup proton acceleration in the ramp or downstream of the shock beyond the energy which specularly reflected ions gain by the motional electric field of the solar wind during their upstream gyration.

DOI： 10.5194/angeo-25-283-2007

Language：Japanese  

Language：English   Publishing type：Research paper (scientific journal)  

Kinetic effects on the parametric decays of Alfvén waves in relativistic pair plasmas

Other Link： http://www.terrapub.co.jp/journals/EPS/pdf/2006/5809/58091213.pdf

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1186/bf03352012

Language：English   Publishing type：Research paper (scientific journal)  

We review recent studies on mass ratio dependence of self-reformation of high Mach number, low beta, highly oblique quasi-perpendicular shocks by Scholer et al. (Scholer, M., Shinohara, L, Matsukiyo, S. Quasi-perpendicular shocks: length scale of the cross-shock potential, shock reformation, and implication for shock surfing, J. Geophys. Res., 108, 1014, doi:10.1029/2002JA009515, 2003), Matsukiyo and Scholer (Matsukiyo, S., Scholer, M. Modified two-stream instability in the foot of high Mach number quasi-perpendicular shocks, J. Geophys. Res., 108, 1459, doi:10.1029/2003JA10080, 2003), and Scholer and Matsukiyo (Scholer, M., Matsukiyo, S. Nonstationarity of quasi-perpendicular shocks: a comparison of full particle simulations with different ion to electron mass ratio, Ann. Geophys., in press, 2004). A one-dimensional full particle simulation code is utilized. In small ion to electron mass ratio runs, reformation is due to the accumulation of gyrating reflected ions at the upstream edge of the foot. Furthermore, at an extremely small mass ratio, the Buneman instability is generated in the foot. In the realistic mass ratio run, however, the modified two-stream instability excited in the foot plays an important role in a shock reformation process. (c) 2006 COSPAR. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.asr.2004.08.012

Language：English   Publishing type：Research paper (scientific journal)  

Microinstabilities excited in the foot of a supercritical perpendicular shock wave are investigated. A two-dimensional full particle simulation with periodic boundary conditions in both directions using the physical ion to electron mass ratio is performed as a proxy for the foot region where incoming and specularly reflected ions overlap. The simulation shows that six types of different instabilities are excited in a time period shorter than ion gyroperiod of the reflected ions. The most dominant instability is the modified two-stream instability, which leads to strong parallel electron heating through a so-called two step instability and to ion phase space holes. Copyright 2006 by the American Geophysical Union.

DOI： 10.1029/2005JA011409

Language：English   Publishing type：Research paper (international conference proceedings)  

On Kinetic Structure of Quasi-Perpendicular Collisionless Shocks

DOI： 10.1063/1.2032669

Language：English   Publishing type：Research paper (other academic)  

We discuss one-dimensional electromagnetic full particle simulations of quasi-perpendicular collisionless shocks with physical mass ratio in the context of recent Cluster bow shock measurements. The density ramp scale in units of the ion inertial length obtained from simulations of high ion beta shocks (beta(i) approximate to 1) does not increase with Mach number, contrary to what has been reported from Earth's bow shock measurements. Several possibilities are offered which could explain this discrepancy. In low beta shocks the modified two-stream instability is important in the foot of the shock and can lead to large density and electric field spikes. It is suggested that recent Cluster observations of short scale electric field spikes at the quasi-perpendicular Earth's bow shock can be explained in terms of the modified two-stream instability.

Language：English  

Language：English  

Language：English  

Language：English  

Language：English   Publishing type：Research paper (scientific journal)  

Nonstationarity of quasi-perpendicular shocks: a comparison of full particle simulations with different ion to electron mass ratio

Other Link： http://www.ann-geophys.net/22/2345/2004/angeo-22-2345-2004.html

Language：Others   Publishing type：Research paper (scientific journal)  

Abstract. We have performed 3 one-dimensional full particle electromagnetic simulations of a quasi-perpendicular shock with the same Alfvén Mach number MA=4.5, shock normal - magnetic field angle ΘBn=87°, and ion and electron beta (particle to magnetic field pressure) of 0.05, but with different ion to electron mass ratios (mi/me=80, 400, 1840). At high ion beta it has been shown previously that the shock is steady. At low ion beta, as in the present simulations, the shock periodically reforms itself. However, whereas at unrealistically low mass ratios the reformation is due to accumulation of specularly reflected particles at the upstream edge of the foot, at the realistic mass ratio the modified two-stream instability between the incoming solar wind ions and solar wind electrons leads to ion phase mixing and thermalization. The reformation process is thereby considerably modified. At the lowest mass ratio the Buneman instability between the solar wind electrons and the reflected ions is excited, which is stabilized at higher mass ratios.

DOI： 10.5194/angeo-22-2345-2004

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1029/2004ja010477

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1029/2003ja010080

Language：English   Publishing type：Research paper (scientific journal)  

Parametric instabilities of circularly polarized Alfvén waves in a relativistic electron-positron plasma
Dispersion relation and nonlinear evolution of the parametric instabilities of circularly polarized Alfvén waves in a relativistic electron-positron plasma are investigated by theoretical and numerical approaches. In the nonrelativistic limit, when [Formula presented] the characteristics of the instabilities are similar to those in an electron-ion plasma, except that the modulational instability takes place only if [Formula presented] where [Formula presented] and [Formula presented] denote the plasma frequency and the acoustic speed, and [Formula presented] [Formula presented] indicate the frequency and the wave number of the parent wave. On the other hand, when [Formula presented] two new types of instabilities emerge between the parallel or antiparallel propagating Alfvén-like waves and the parallel propagating Langmuir-like wave. The weakly relativistic effect is discussed for all the instabilities. The one-dimensional full particle simulation and bicoherence analysis of the simulation result suggest that successive decay via the interaction between the parallel propagating Langmuir-like wave and antiparallel propagating Alfvén-like wave can efficiently generate a continuum of low frequency electromagnetic waves, which can interact with energetic particles. © 2003 The American Physical Society.

DOI： 10.1103/PhysRevE.67.046406

Language：English   Publishing type：Research paper (scientific journal)  

Quasi-perpendicular shocks: Length scale of the cross-shock potential, shock reformation, and implication for shock surfing

DOI： 10.1029/2002JA009515

Other Link： http://www.agu.org/pubs/crossref/2003/2002JA009515.shtml

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1029/2002ja009515

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1063/1.1431593

Language：Japanese  

Other Link： http://www.tj.kyushu-u.ac.jp/info/online/index.php?lang=ja

Repository Public URL： http://hdl.handle.net/2324/16643

Language：English  

Other Link： http://www.tj.kyushu-u.ac.jp/info/online/index.php?lang=ja

Repository Public URL： http://hdl.handle.net/2324/16615

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1143/jpsj.68.1049

Language：Japanese  

Language：English  

Event date： 2024.3

Language：Japanese  

Venue：名古屋市   Country：Japan  

researchmap

Event date： 2024.1

Language：English   Presentation type：Oral presentation (invited, special)  

Venue：春日市   Country：Japan  

Nonstationarity of a Collisionless Shock

Event date： 2024.1

Language：English  

Venue：春日市   Country：Japan  

researchmap

Event date： 2023.11

Language：English   Presentation type：Oral presentation (invited, special)  

Venue：Nagoya   Country：Japan  

Effects of heliospheric boundary in the behaviors of galactic and anomalous cosmic rays

Other Link： https://www.aappsdpp.org/DPP2023/html/3contents/plenary.html

Event date： 2023.11

Language：English  

Venue：Nagoya   Country：Japan  

researchmap

Event date： 2022.11 - 2022.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Korea   Country：Other  

Gekko XII High Power Laser Experiment and Numerical Simulation on Developing Supercritical Magnetized Shock

Other Link： http://icpp2022.kr/

Event date： 2022.10 - 2022.11

Language：English   Presentation type：Oral presentation (general)  

Venue：USA   Country：Other  

Properties of cosmic ray test particles invading the virtual heliosphere in global MHD simulation

Other Link： https://www.icnsmeetings.com/conference/20thannual/index.html

Event date： 2022.5

Language：English  

Venue：online   Country：Other  

Properties of cosmic ray test particles in global MHD simulation of the heliosphere

Other Link： https://earth.esa.int/eogateway/events/egu-general-assembly-2022

Event date： 2021.10 - 2021.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Online   Country：Japan  

Other Link： http://sgepss.org/sgepss/sookai/150/index.html

Event date： 2021.9 - 2021.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Online   Country：Other  

Other Link： http://aappsdpp.org/DPP2021/index.html

Event date： 2021.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Online   Country：Japan  

Event date： 2020.12

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：Online   Country：United States  

In the heliospheric boundary region matter and energy are extensively transported and/or converted between the heliosphere and the local interstellar space. This region has been explored in-situ by Voyager spacecraft in this century. Voyager spacecraft revealed a lot of features of the two important discontinuities, termination shock and heliopause, as well as unexpected properties of high energy particles in the boundary region. Some of the features have been still not well understood. We first review our full particle-in-cell simulation studies to discuss kinetic properties of the two discontinuities. Then, we further discuss our recent work on the effect of global structure of the heliosphere in the cosmic ray invasion process into the heliosphere.

Other Link： https://www.agu.org/Fall-Meeting-2020

Event date： 2020.10

Language：English   Presentation type：Oral presentation (invited, special)  

Venue：Online   Country：Other  

Heliosphere is a bubble occupied by the solar wind plasma and magnetic field in the local interstellar space. Matter and energy are actively transported and/or converted in the boundary region between the heliosphere and the local interstellar space. This region has been explored in-situ by Voyager spacecraft in this century1-18. Voyager spacecraft revealed a lot of features, some of which have been still unresolved, such as complex structures of two important discontinuities, unexpected properties of high energy particles, etc. In this study we first focus on the kinetic structures of the termination shock and the heliopause. Using particle-in-cell simulation, kinetic structure of the transition region of these discontinuities are investigated. In the termination shock the roles of pickup ions are examined carefully19-22. Kinetic structure of the heliopause influenced by the termination shock is also studied3. In the second part of this study the effect of global structure of the heliosphere in the cosmic ray invasion process is considered. It has been unknown how galactic cosmic rays enter and reach deep inside the heliosphere. To understand the cosmic ray invasion process in the level of particle trajectory, we perform a test particle simulation in the global electromagnetic structure of the heliosphere reproduced by using high resolution 3D MHD simulation. A number of characteristic trajectories of different energy cosmic ray particles are reported.

Other Link： http://aappsdpp.org/DPP2020/index.html

Event date： 2019.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Hefei   Country：China  

Kinetic radial structure of heliospheric boundary
Abstract: The kinetic structure of the heliospheric boundary region is investigated using one-dimensional full PIC (Particle-In-Cell) simulations. A shock tube problem is numerically solved under the condition that a relatively tenuous and weakly magnetized plasma, mimicking the solar wind (SW) plasma, is continuously pushed by a relatively dense and strongly magnetized plasma, mimicking the interstellar (IS) plasma, having supersonic relative velocity. A forward and a reverse shock, corresponding to the SW termination shock and the IS bow shock, and a contact discontinuity, to the heliopause, are self-consistently reproduced. The spatial width of the heliopause increases as the angle between the discontinuity normal and ambient magnetic field decreases. The inner structure of the heliopause shows different profiles between magnetic field and plasma density, or pressure, which is caused by a non-MHD effect of the local plasma. The region between the two shocks is turbulent. The turbulence in the relatively dense plasma, corresponding to the outer heliosheath, is compressible and propagating away from the heliopause, although the turbulence in the relatively tenuous plasma, corresponding to the inner heliosheath, contains both compressible and incompressible fluctuations. The source of the compressible turbulence in the outer heliosheath is in the inner heliosheath. Only compressible fast mode fluctuations generated in the inner heliosheath are transmitted through the heliopause and propagate in the outer heliosheath. The results are discussed in the context of recent observations by Voyager spacecraft.

Other Link： http://aappsdpp.org/DPP2019/index.html

Event date： 2019.7

Language：English   Presentation type：Oral presentation (general)  

Venue：Busan   Country：Korea, Republic of  

A high beta shock has not been paid much attention from the aspect of particle acceleration, since it is a relatively weak shock so that its structure is more or less laminar and steady where the activities of waves are generally thought to be low. In space, on the other hand, a number of high beta shocks are observed and some of them indicate the evidence of particle acceleration. We found that relativistic shock drift acceleration followed by reflection efficiently works at such a high beta shock by using one-dimensional full particle-in-cell (PIC) simulation. This mechanism is suppressed, however, when the effect of higher dimension is taken into account due to the rippled structure of shock surface. We further consider the presence of halo electrons which are the non-thermal component often observed also in the solar wind. Then, it is found that the halo electrons are preferentially accelerated and reflected. Its efficiency appears to be increased due to the rippled structure.

Other Link： http://sirius.unist.ac.kr/kaw10/

Event date： 2019.2

Language：English   Presentation type：Oral presentation (general)  

Venue：Pasadena   Country：United States  

The kinetic structure of the heliospheric boundaries is investigated using one-dimensional full PIC (Particle-In-Cell) simulations. Both the termination shock and the heliopause are simultaneously reproduced in the simulation. The spatial scale of the heliopause increases as the angle between the heliopause normal and local magnetic field (referred to as the normal angle, hereafter) becomes increasingly oblique. The total pressure, including the plasma pressure and magnetic pressure, at the heliopause is not constant when the normal angle is oblique in contrast to predictions based on MHD theory. In the oblique case, the solar wind plasma and interstellar plasma are able to inter-penetrate by moving along the local magnetic field. Since their bulk velocities along the magnetic field differ from each other, the distributions overlap in phase space so that the effective local plasma pressure parallel to the magnetic field is enhanced. This results in an increase that resembles a hump in the density and
parallel pressure of the local plasma, which is not seen in magnetic field.

Other Link： https://www.icnsmeetings.com/conference/18thannual/index.html

Event date： 2018.11

Language：English   Presentation type：Oral presentation (general)  

Venue：金沢市   Country：Japan  

Electron acceleration in a high beta and low Mach number quasi-perpendicular collisionless shock is investigated by using one- and two-dimensional full particle-in-cell simulations. In contrast to low beta or high Mach number shocks, relativistic shock drift acceleration followed by reflection is observed in one-dimensional simulation. However, the reflection is suppressed due to the effect of shock surface rippling in two-dimensional simulations, while less efficient reflection is confirmed when shock angle is deviated from perpendicular (The shock angle is defined as the angle between shock normal and upstream magnetic field.). Structure of the shock transition region is much more complicated than previously expected, in spite of the high beta and low Mach number situation. Not only ion scale fluctuations, including the ripple, but also electron scale fluctuations are seen. Among these, downstream fluctuations are dominated by electromagnetic ion cyclotron instability and/or mirror instability, electron scale fluctuations in the overshoot (foot) are due to whistler instability (modified two-stream instability). Relative importance of the instabilities changes with the shock angle. We further studied the behavior of halo electrons whose temperature is one order higher than background upstream electrons. By assuming that relative density of the halo electrons is sufficiently low so that their dynamics do not affect the behavior of electromagnetic fields, the halo electrons are treated as test particles. We found that the halo electrons are preferentially reflected after being accelerated through the shock drift mechanism even if the shock surface ripple is present. They are also heated more efficiently than the background electrons.

Other Link： http://aappsdpp.org/DPP2018/index.html

Event date： 2018.3

Language：English   Presentation type：Oral presentation (general)  

Venue：Santa Fe   Country：United States  

Microstructure of heliospheric boundary is investigated by using full PIC (Particle-In-Cell) simulations. Both the termination shock and the heliopause are simultaneously reproduced by using the PIC simulation, although system size is very limited and a strong assumption of one-dimensionality is imposed. Spatial scale of the heliopause increases as the angle between the heliopause normal and interstellar magnetic field becomes oblique. The downstream of the termination shock, the region between the termination shock and the heliopause, contains large amplitude magnetic as well as density fluctuations. The VLISM region also contains some fluctuations in magnetic field and density. We investigated the origin and the characteristics of those fluctuations. The density fluctuations show partly positive and partly negative correlations with the magnetic fluctuations in the downstream of the termination shock. The positively correlated fluctuations are produced in the shock front through the self-reformation process, while the negatively correlated ones are generated through mirror instability. On the other hand, the fluctuations in the VLISM show only positive correlation between magnetic and density fluctuations. Further, the fluctuations propagate from the heliopause to the VLISM, which implies that those fluctuations are originated from the heliosphere.

Other Link： https://www.icnsmeetings.com/conference/17thannual/index.html

Event date： 2017.4

Language：English   Presentation type：Oral presentation (general)  

Venue：Vienna   Country：Austria  

Electromagnetic structure of a quasi-parallel shock is highly complex. From the viewpoint of numerical kinetic simulation, quite large simulation domain is necessary to reproduce a foreshock region where some particles are back streaming almost freely along the ambient magnetic field. This may be a main reason that full particle-in-cell (PIC) simulations of a quasi-parallel shock have been seldom performed, although there are only a few examples.

Here, both ion and electron scale structures of the foreshock in a quasi-parallel shock are investigated by using one-dimensional full PIC simulation with sufficiently large system size (= 2500 ion inertial lengths). The shock parameters are as follows. The Alfven Mach number is 6.6, upstream ion and electron betas are both 0.5, and the shock angle is 20 deg. The ion to electron mass ratio is 64, the ratio of electron plasma to cyclotron frequency is 12.5. Well developed large amplitude MHD waves, evolution of back streaming ion distribution function, electron scale structure grown in the MHD scale structure, and dynamics of high energy particles are discussed.

Other Link： https://www.egu2017.eu/

Event date： 2016.7 - 2017.7

Language：English   Presentation type：Oral presentation (general)  

Venue：Tsukuba   Country：Japan  

In a collisionless shock microinstabilities play important roles. They heat an incoming plasma to provide necessary dissipation in a transition region. They are sometimes able to directly produce non-thermal particles. Furthermore, they produce a scatterer of the non-thermal particles in the context of diffusive shock acceleration (DSA). We review the above mentioned roles of microinstabilities in some cases of quasi-perpendicular shocks from the viewpoint of full particle-in-cell simulation.
First, we focus on the instabilities generated in the so-called foot region, which is produced by the ions specularly reflected at the shock (ramp). The reflected ions become a beam in terms of the incoming plasma so that some microinstabilities get excited. Depending on the shock parameters a variety of instabilities are generated. Here, we introduce electron thermal Mach number, Mte, defined as the upstream flow velocity normalized to electron thermal velocity, which is proportional to Alfven Mach number divided by the square root of electron beta. When the Mach number is low, Mte ≲ 1, as in the Earth’s bow shock, electron cyclotron-drift instability, and modified two-stream instability are dominantly generated. These instabilities contribute to electron as well as ion heating. For higher Mach numbers, Mte >> 1, Buneman instability gets excited. The resultant large amplitude waves trap some electrons which are accelerated by the convection electric field to non-thermal energy while being trapped.
On the other hand, when Mte < cosBn (B2/B1)1/2, non-negligible amount of electrons are mirror reflected at a shock. The reflected electrons form a foreshock. In the foreshock resonant and non-resonant instabilities are generated. The latter is also called electron firehose instability and efficiently scatter the reflected electrons. The waves play crucial roles in injection of non-thermal electrons into DSA.

Other Link： http://www.icehap.chiba-u.jp/activity/EASW2016/index.html

Event date： 2015.8

Language：English   Presentation type：Oral presentation (general)  

Venue：POSCO International Center   Country：Japan  

Other Link： https://apctp.org/plan.php/eastplasma2015/

Event date： 2015.4

Language：English   Presentation type：Oral presentation (general)  

Venue：Sheraton Tampa Riverwalk Hotel   Country：United States  

Other Link： https://www.icnsmeetings.com/conference/14thannual/index.html

Event date： 2014.2

Language：English   Presentation type：Oral presentation (general)  

Venue：大阪大学レーザーエネルギー学研究センター   Country：Japan  

Event date： 2013.9

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：徳島大学   Country：Japan  

Event date： 2013.6

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：Institut d'Astrophysique de Paris   Country：France  

Other Link： http://www.iap.fr/Collisionless_Shocks/index.html

Event date： 2013.5

Language：English   Presentation type：Oral presentation (general)  

Venue：Cancun Center, Cancun   Country：Mexico  

The ability of the termination shock as a particle accelerator is totally unknown. Voyager data and recent kinetic numerical simulations revealed that the compression ratio of the termination shock is rather low due to the presence of pickup ions, i.e., the termination shock appears to be a weak shock. Nevertheless, two Voyager spacecraft observed not only high energy ions called termination shock particles, which are non-thermal but less energetic compared to the so-called anomalous cosmic rays, but also high energy electrons. In this study we focus especially on microstructure of the termination shock and the associated electron acceleration process by performing one-dimensional full particle-in-cell (PIC) simulations for a variety of parameters. For typical solar wind parameters at the termination shock, a shock potential has no sharp ramp with the spatial scale of the order of electron inertial length which is suitable for the injection of anomalous cosmic ray acceleration. Solar wind ions are not so much heated, which is consistent with Voyager spacecraft data. If a shock angle is close to 90 deg., a shock is almost time stationary or weakly breathing when a relative pickup ion density is 30&#37;, while it becomes non-stationary if the relative pickup ion density is 20&#37;. When the shock angle becomes oblique, a self-reformation occurs due to the interaction of solar wind ions and whistler precursors. Here, the shock angle is defined as the angle between upstream magnetic field and shock normal. For the case with relatively low beta solar wind plasma (electron beta is 0.1 and solar wind ion temperature equals to electron temperature), modified two-stream instability (MTSI) gets excited in the extended foot sustained by reflected pickup ions, and both solar wind electrons and ions are heated. If the solar wind plasma temperature gets five times higher, on the other hand, the MTSI is weakened and the pre-heating of the solar wind plasma in the extended foot is suppressed. Although the electron acceleration rate is not so much dependent on these microstructures, it depends on the shock angle. The shock drift acceleration efficiently occurs for oblique shocks.

Other Link： http://moa.agu.org/2013/

Event date： 2012.8

Language：English   Presentation type：Oral presentation (general)  

Venue：Resorts World Convention Centre, Singapore   Country：Singapore  

Microstructure of the termination shock reproduced by one-dimensional full particle-in-cell (PIC) simulations is investigated. For typical solar wind parameters at the termination shock, a shock potential has no sharp ramp with the spatial scale of the order of electron inertial length which is suitable for the injection of anomalous cosmic ray acceleration. Solar wind ions are not so much heated, which is consistent with Voyager spacecraft data. These features are due to the presence of pickup ions. Furthermore, when a relative pickup ion density is 30&#37;, a shock is time stationary. For the case with low beta (=0.17) solar wind plasma, modified two-stream instability (MTSI) gets excited in the extended foot sustained by reflected pickup ions, and both solar wind electrons and ions are heated. If the solar wind plasma beta gets five times higher (=0.85), on the other hand, the MTSI is weakened and the pre-heating of the solar wind plasma in the extended foot is suppressed. Other parameter dependence of detailed shock structure on relative pickup ion density, Alfven Mach number, ion-to-electron mass ratio, and electron plasma to cyclotron frequency ratio is discussed.

Other Link： http://www.asiaoceania.org/aogs2012/

Event date： 2011.8

Language：English   Presentation type：Oral presentation (general)  

Venue：National Cheng Kung University   Country：Taiwan, Province of China  

Full Particle Simulation on Microstructure of Heliospheric Termination Shock

Other Link： http://www.pssc.ncku.edu.tw/ISPS_2011/index.html

Event date： 2011.7

Language：English   Presentation type：Oral presentation (general)  

Venue：Banff Conference Centre   Country：Canada  

Other Link： http://www.ualberta.ca/~isss10/

Event date： 2010.6

Language：English   Presentation type：Oral presentation (general)  

Venue：National Cheng Kung University, Tainan, Taiwan   Country：Taiwan, Province of China  

Other Link： http://www.pssc.ncku.edu.tw/ISPS_2010/

Event date： 2009.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Asia Pacific Center for Theoretical Physics (APCTP)   Country：Korea, Republic of  

Other Link： http://canopus.cnu.ac.kr/kaw5/

Event date： 2009.5

Language：English   Presentation type：Oral presentation (general)  

Venue：Sheraton Keauhou Resort and Spa (Big Island of Hawaii)   Country：United States  

Other Link： http://www.icnsmeetings.com/conference/8thannual/

Event date： 2008.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Jagiellonian University Conference Center   Country：Poland  

Other Link： http://www.oa.uj.edu.pl/cracow2008/

Event date： 2008.4

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：La Berlugane Hotel (Beaulieu）   Country：France  

Event date： 2008.1

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：千里阪急ホテル（豊中市）   Country：Japan  

Event date： 2007.7 - 2007.8

Language：English   Presentation type：Oral presentation (general)  

Venue：Queen Sirikit National Convention Center (Bangkok)   Country：Thailand  

Other Link： http://www.asiaoceania.org/aogs2007/

Event date： 2007.4

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：National Fusion Research Center (Daejeon)   Country：Korea, Republic of  

Other Link： http://canopus.cnu.ac.kr/lsap/jpn-kor07.htm

Event date： 2007.2

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：東京工業大学   Country：Japan  

Language：English   Presentation type：Oral presentation (general)  

Venue：International Plaza, Kyushu University   Country：Japan  

Other Link： http://www.esst.kyushu-u.ac.jp/~nlw/

Language：English   Presentation type：Oral presentation (general)  

Venue：Caesar Resort Hotels: Dead Sea   Country：Israel  

Language：English   Presentation type：Oral presentation (general)  

Venue：Vigyan Bhavan   Country：India  

Event date： 2023.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Nagoya   Country：Japan  

Inner structure of a magnetic island in collisionless reconnection

Other Link： https://www.aappsdpp.org/DPP2023/html/3contents/topical.html

Event date： 2023.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Nagoya   Country：Japan  

Relativistic particle acceleration in two-dimensional Alfvén wave turbulence

Other Link： https://www.aappsdpp.org/DPP2023/html/3contents/topical.html

Event date： 2023.11

Language：English  

Venue：Nagoya   Country：Japan  

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Event date： 2023.11

Language：English  

Venue：Nagoya   Country：Japan  

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Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台市   Country：Japan  

The Impact of the Geomagnetic Storm Event of February 2022 on the Inner Radiation Belt by Test Particle Simulations

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台市   Country：Japan  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台市   Country：Japan  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台市   Country：Japan  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台市   Country：Japan  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台市   Country：Japan  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台市   Country：Japan  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台市   Country：Japan  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台市   Country：Japan  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台市   Country：Japan  

Event date： 2023.9

Language：Japanese  

Venue：仙台市   Country：Japan  

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Event date： 2023.9

Language：Japanese  

Venue：仙台市   Country：Japan  

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Event date： 2023.9

Language：Japanese  

Venue：仙台市   Country：Japan  

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Event date： 2023.9

Language：Japanese  

Venue：仙台市   Country：Japan  

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Event date： 2023.9

Language：Japanese  

Venue：仙台市   Country：Japan  

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Event date： 2023.9

Language：Japanese  

Venue：仙台市   Country：Japan  

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Event date： 2023.9

Language：Japanese  

Venue：仙台市   Country：Japan  

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Event date： 2023.9

Language：Japanese  

Venue：仙台市   Country：Japan  

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Event date： 2023.9

Language：Japanese  

Venue：仙台市   Country：Japan  

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Event date： 2023.9

Language：Japanese  

Venue：仙台市   Country：Japan  

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Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台市   Country：Japan  

Other Link： https://onsite.gakkai-web.net/jps/jps_search/2023au/index_e.html

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台市   Country：Japan  

Other Link： https://onsite.gakkai-web.net/jps/jps_search/2023au/index_e.html

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台市   Country：Japan  

Other Link： https://onsite.gakkai-web.net/jps/jps_search/2023au/index_e.html

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台市   Country：Japan  

Other Link： https://onsite.gakkai-web.net/jps/jps_search/2023au/index_e.html

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台市   Country：Japan  

Other Link： https://onsite.gakkai-web.net/jps/jps_search/2023au/index_e.html

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台市   Country：Japan  

Other Link： https://onsite.gakkai-web.net/jps/jps_search/2023au/index_e.html

Event date： 2023.9

Language：Japanese  

Venue：仙台市   Country：Japan  

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Event date： 2023.9

Language：Japanese  

Venue：仙台市   Country：Japan  

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Event date： 2023.9

Language：Japanese  

Venue：仙台市   Country：Japan  

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Event date： 2023.9

Language：Japanese  

Venue：仙台市   Country：Japan  

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Event date： 2023.9

Language：Japanese  

Venue：仙台市   Country：Japan  

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Event date： 2023.9

Language：Japanese  

Venue：仙台市   Country：Japan  

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Event date： 2023.8

Language：English   Presentation type：Oral presentation (general)  

Venue：Sapporo   Country：Japan  

Microstructure of magnetic island in collisionless reconnection

Other Link： https://www.ursi-gass2023.jp/about.html

Event date： 2023.8

Language：English  

Venue：Sapporo   Country：Japan  

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Event date： 2023.7 - 2023.8

Language：English  

Venue：Nagoya   Country：Japan  

Shock parameter dependence of electron acceleration at quasi-perpendicular collisionless shock

Event date： 2023.7 - 2023.8

Language：English  

Venue：Nagoya   Country：Japan  

Effects of heliospheric boundary structures on galactic cosmic ray transport : Global MHD and large-scale test particle simulations

Event date： 2023.7 - 2023.8

Language：English  

Venue：Nagoya   Country：Japan  

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Event date： 2023.7 - 2023.8

Language：English  

Venue：Nagoya   Country：Japan  

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Event date： 2023.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：吹田市   Country：Japan  

Event date： 2023.6

Language：Japanese  

Venue：吹田市   Country：Japan  

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Event date： 2023.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：千葉市   Country：Other  

Other Link： https://www.jpgu.org/meeting_e2023/

Event date： 2023.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：千葉市   Country：Other  

Other Link： https://www.jpgu.org/meeting_e2023/

Event date： 2023.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：千葉市   Country：Other  

Other Link： https://www.jpgu.org/meeting_e2023/

Event date： 2023.5

Language：Japanese  

Venue：千葉市  

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Event date： 2023.5

Language：Japanese  

Venue：千葉市  

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Event date： 2023.5

Language：Japanese  

Venue：千葉市  

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Event date： 2023.3

Language：English  

Country：Other  

Numerical simulation on invasion process of galactic cosmic rays into the heliosphere: Particle orbits and statistics

Event date： 2023.3

Language：English   Presentation type：Symposium, workshop panel (public)  

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Event date： 2023.3

Language：English   Presentation type：Oral presentation (general)  

Country：Other  

Relativistic particle acceleration in counter-propagating Alfven/whistler waves

Event date： 2023.3

Language：English  

Country：Other  

Relativistic particle acceleration in counter-propagating Alfven/whistler waves

Event date： 2023.3

Language：English   Presentation type：Oral presentation (general)  

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Event date： 2022.11 - 2022.12

Language：English   Presentation type：Oral presentation (invited, special)  

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Event date： 2022.11

Language：Japanese  

Country：Other  

Relativistic particle acceleration in 2D Alfven wave turbulence

Event date： 2022.11

Language：Japanese  

Country：Other  

Electron betatron and shock drift acceleration at reforming quasi-perpendicular shocks

Event date： 2022.11

Language：English  

Country：Other  

How do the geomagnetic storms affect the LEO proton flux distribution during Solar Energetic Particle events?

Event date： 2022.11

Language：English  

Country：Other  

Mass ratio dependence of microinstability in a magnetic island formed through magnetic reconnection

Event date： 2022.11

Language：Japanese  

Country：Other  

Relativistic resonant particle acceleration by counter propagating Alfven waves

Event date： 2022.11

Language：Japanese  

Country：Other  

2D kinetic structure of PUI mediated oblique shock

Event date： 2022.11

Language：Japanese  

Country：Other  

Space-time resolved measurement of magnetic diffusion region of magnetic reconnection in laser-produced plasma

Event date： 2022.11

Language：Japanese  

Country：Other  

Estimation of plasma parameters by deep learning based on physical laws

Event date： 2022.11

Language：Japanese  

Country：Other  

PIC simulation on parametric instability of a large amplitude electromagnetic wave in a relativistic electron-positron plasma

Event date： 2022.11

Language：Japanese  

Country：Other  

High power laser experiment on the long time evolution of magnetized plasma shock

Event date： 2022.11

Language：Japanese   Presentation type：Poster presentation  

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Event date： 2022.11

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2022.11

Language：English   Presentation type：Oral presentation (general)  

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Event date： 2022.11

Language：English   Presentation type：Oral presentation (general)  

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Event date： 2022.11

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2022.11

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2022.11

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2022.11

Language：Japanese   Presentation type：Poster presentation  

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Event date： 2022.11

Language：Japanese   Presentation type：Poster presentation  

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Event date： 2022.11

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2022.10 - 2022.11

Language：English   Presentation type：Oral presentation (invited, special)  

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Event date： 2022.10

Language：English  

Country：Other  

Trajectory Analysis of Galactic Cosmic Ray Protons Invading the Virtual Heliosphere

Event date： 2022.10

Language：English   Presentation type：Public lecture, seminar, tutorial, course, or other speech  

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Event date： 2022.10

Language：English  

Country：Other  

Large-scale test particle simulation of galactic cosmic rays invading the heliosphere

Event date： 2022.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Online   Country：Other  

Other Link： http://aappsdpp.org/DPP2022/html/1about/home.html

Event date： 2022.10

Language：English   Presentation type：Oral presentation (invited, special)  

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Event date： 2022.6

Language：Japanese  

Country：Other  

Empirical research of self-reformation of collisionless shock

Event date： 2022.6

Language：Japanese   Presentation type：Poster presentation  

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Event date： 2022.5

Language：English   Presentation type：Oral presentation (invited, special)  

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Event date： 2022.5 - 2022.6

Language：Japanese  

Country：Other  

Statistical behavior of galactic cosmic rays in the steady heliosphere

Event date： 2022.5 - 2022.6

Language：Japanese  

Country：Other  

3D PIC simulations of coherent emission from relativistic shocks

Event date： 2022.5 - 2022.6

Language：Japanese  

Country：Other  

Shock Drift Acceleration and Betatron Acceleration of Electrons at Nonstationary Quasi-Perpendicular Shocks

Event date： 2022.5 - 2022.6

Language：Japanese  

Country：Other  

Numerical simulation on the production of anomalous cosmic rays in the heliospheric termination shock

Event date： 2022.5 - 2022.6

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2022.5 - 2022.6

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2022.5 - 2022.6

Language：Japanese   Presentation type：Poster presentation  

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Event date： 2022.5 - 2022.6

Language：Japanese   Presentation type：Poster presentation  

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Event date： 2022.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：online   Country：Japan  

Event date： 2022.5

Language：Japanese  

Venue：online   Country：Japan  

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Event date： 2022.3

Language：Japanese  

Country：Other  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2022.3

Language：Japanese  

Country：Other  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2022.1

Language：Japanese  

Country：Other  

Particle acceleration in parametric instabilities of relativistic MHD waves

Event date： 2022.1

Language：Japanese   Presentation type：Public lecture, seminar, tutorial, course, or other speech  

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Event date： 2021.12

Language：English   Presentation type：Oral presentation (general)  

Venue：New Orleans/Online   Country：United States  

Other Link： https://www.agu.org/Fall-Meeting-2021

Event date： 2021.12

Language：English   Presentation type：Oral presentation (general)  

Venue：New Orleans/Online   Country：United States  

Other Link： https://www.agu.org/Fall-Meeting-2021

Event date： 2021.10 - 2021.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Online   Country：Japan  

Other Link： http://sgepss.org/sgepss/sookai/150/index.html

Event date： 2021.10 - 2021.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Online   Country：Japan  

Other Link： http://sgepss.org/sgepss/sookai/150/index.html

Event date： 2021.10 - 2021.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Online   Country：Japan  

Other Link： http://sgepss.org/sgepss/sookai/150/index.html

Event date： 2021.10 - 2021.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Online   Country：Japan