Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Shuichi Matsukiyo Last modified date:2021.06.30

Associate Professor / Space Environmental Fluid Dynamics / Department of Advanced Environmental Science and Engineering / Faculty of Engineering Sciences


Papers
1. Ligorini, A.; Niemiec, J.; Kobzar, O.; Iwamoto, M.; Bohdan, A.; Pohl, M.; Matsumoto, Y.; Amano, T.; Matsukiyo, S.; Hoshino, M., Mildly relativistic magnetized shocks in electron-ion plasmas - II. Particle acceleration and heating, Monthly Notices of the Royal Astronomical Society, 10.1093/mnras/stab220, 502, 5065-5074, 2021.01, [URL], Particle acceleration and heating at mildly relativistic magnetized shocks in electron-ion plasma are investigated with unprecedentedly high-resolution 2D 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..
2. Ligorini, A.; Niemiec, J.; Kobzar, O.; Iwamoto, M.; Bohdan, A.; Pohl, M.; Matsumoto, Y.; Amano, T.; Matsukiyo, S.; Esaki, Y.; Hoshino, M., Mildly relativistic magnetized shocks in electron-ion plasmas - I. Electromagnetic shock structure, Monthly Notices of the Royal Astronomical Society, 10.1093/mnras/staa3901, 501, 4837-4849, 2021.01, [URL], 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..
3. Sakai, K.; Isayama, S.; Bolouki, N.; Habibi, M. S.; Liu, Y. L.; Hsieh, Y. H.; Chu, H. H.; Wang, J.; Chen, S. H.; Morita, T.; Tomita, K.; Yamazaki, R.; Sakawa, Y.; Matsukiyo, S.; Kuramitsu, Y., Collective Thomson scattering in non-equilibrium laser produced two-stream plasmas, Physics of Plasmas, 10.1063/5.0011935, 27, 103104(1)-103104(13), 2020.10, [URL], We investigate collective Thomson scattering (CTS) in two-stream non-equilibrium plasmas analytically, numerically, and experimentally. In laboratory astrophysics, CTS is a unique tool to obtain local plasma diagnostics. While the standard CTS theory assumes plasmas to be linear, stationary, isotropic, and equilibrium, they are often nonlinear, non-stationary, anisotropic, and non-equilibrium in high energy phenomena relevant to laboratory astrophysics. We theoretically calculate and numerically simulate the CTS spectra in two-stream plasmas as a typical example of a non-equilibrium system in space and astrophysical plasmas. The simulation results show the feasibility to diagnose two-stream instability directly via CTS measurements. To confirm the non-equilibrium CTS analysis, we have developed an experimental system with a high repetition rate tabletop laser for laboratory astrophysics..
4. Matsukiyo, S., Parametric instabilities in a two ion species plasma as a driver of super Alfvenic waves, Journal of Physics: Conference Series, 10.1088/1742-6596/1620/1/012013, 1620, 012013(1)-012013(12), 2020.09, [URL].
5. Yang, Z.; Liu, Y. D.; Matsukiyo, S.; Lu, Q.; Guo, F.; Liu, M.; Xie, H.; Gao, X.; Guo, J., PIC simulations of microinstabilities and waves at near-sun solar wind perpendicular shocks: Predictions for Parker Solar Probe and Solar Orbiter, The Astrophysical Journal Letters, 10.3847/2041-8213/abaf59, 900, 2, L24(1)-L24(8), 2020.09, [URL], PIC Simulation of a Shock Tube: Implications for Wave Transmission in the Heliospheric Boundary Region.
6. Morita, T.; Tomita, K.; Sakai, K.; Takagi, M.; Aihara, K.; Edamoto, M.; Egashira, S.; Higuchi, T.; Ishizaka, N.; Izumi, T.; Kakuchi, S.; Kojima, T.; Kuramitsu, Y.; Matsukiyo, S.; Nakagawa, Y.; Minami, T.; Murakami, H.; Nishioka, Y.; Ota, M.; Sano, T. Sei, S.; Sugiyama, K.; Tanaka, S. J.; Yamazaki, R.; Sakawa, Y., Local plasma parameter measurements in colliding laser-produced plasmas for studying magnetic reconnection, High Energy Density Physics, 10.1016/j.hedp.2020.100754, 36, 100754(1)-100754(4), 2020.08, [URL], We have implemented laser Thomson scattering for local plasma measurement of electron and ion temperatures, electron density, flow velocity, and charge state. The electron density increases by two times in the interaction of two plasma flows, indicating collisionless interaction. The density and velocity show fluctuations only at t=40 ns, and the density suddenly decreases, indicating the plasma ejection from the interaction region, which can be explained by a magnetic reconnection. The electron temperature in the double-flow is larger than that in the single flow. This may be explained by the energy transfer from the plasma kinetic energy to thermal energy. The ion temperature is much larger than electron temperature in the double-flow, and this may be explained by collisional effects between two plasmas, and/or possibly interpreted as a thermalization due to magnetic reconnection..
7. Girgis, K. M.; Hada, T.; Matsukiyo, S., Solar wind parameter and seasonal variation effects on the south atlantic anomaly using Tsyganenko models, Earth, Planets and Space, 10.1186/s40623-021-01367-7, 72, 1, 100(1)-100(17), 2020.07, [URL], We studied the space weather effects on the South Atlantic Anomaly (SAA) magnetic response using Tsyganenko
models. For the physical parameters characterizing the SAA, the study considered the minimum magnetic field, the location (longitude and latitude) of the SAA center, and the area of the SAA. Regarding the space weather parameters, we considered the solar wind dynamic pressure, the interplanetary magnetic field components, ByIMF and BzIMF , the Dst index, and the geodipole tilting angle. To study the magnetic field response of the SAA, several different versions of the Tsyganenko models, namely, T96, T01, and TS05, were used to describe the external magnetic field contributions. The main internal magnetic field was calculated by the International Geomagnetic Reference Field (IGRF-12). The magnetic field study of the SAA was realized in long- and short-term (seasonal and diurnal) variations. We found that the Dst index and the geodipole tilting angle were the strongest influencing parameters on the SAA magnetic field response at all altitudes. Moreover, it was revealed that both magnetic poles might be a possible cause of the SAA magnetic field response, resulting from the space weather conditions. Furthermore, the magnetic field behavior of the SAA was affected by hourly variations, where the largest changes occurred at dayside..
8. Matsukiyo, S.; Noumi, T.; Zank, G. P.; Washimi, H.; Hada, T., PIC Simulation of a Shock Tube: Implications for Wave Transmission in the Heliospheric Boundary Region, The Astrophysical Journal, 10.3847/1538-4357/ab54c9, 888, 1, 11(1)-11(9), 2020.01, [URL], A shock tube problem is solved numerically by using one-dimensional full particle-in-cell simulations under the condition that a relatively tenuous and weakly magnetized plasma is continuously pushed by a relatively dense and strongly magnetized plasma having supersonic relative velocity. A forward and a reverse shock and a contact discontinuity are self-consistently reproduced. The spatial width of the contact discontinuity increases as the angle between the discontinuity normal and ambient magnetic field decreases. The inner structure of the discontinuity 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 fluctuations in the relatively dense plasma are compressible and propagating away from the contact discontinuity, although the fluctuations in the relatively tenuous plasma contain both compressible and incompressible components. The source of the compressible fluctuations in the relatively dense plasma is in the relatively tenuous plasma. Only compressible fast mode fluctuations generated in the relatively tenuous plasma are transmitted through the contact discontinuity and propagate in the relatively dense plasma. These fast mode fluctuations are steepened when passing the contact discontinuity. This wave steepening and probably other effects may cause the broadening of the wave spectrum in the very local interstellar medium plasma. The results are discussed in the context of the heliospheric boundary region or heliopause..
9. Matsukiyo, S.; Akamizu, T.; Hada, T., Heavy Ion Acceleration by Super-Alfvénic Waves, The Astrophysical Journal Letters, 10.3847/2041-8213/ab58cf, 887, 1, L2(1)-L2(4), 2019.12, [URL], A generation mechanism of super-Alfvénic (SPA) waves in multi-ion species plasma is proposed, and the associated heavy ion acceleration process is discussed. The SPA waves are thought to play important roles in particle acceleration since they have large wave electric fields because of their high phase velocity. It is demonstrated by using full particle-in-cell simulations that large amplitude proton cyclotron waves, excited due to proton temperature anisotropy, nonlinearly destabilize SPA waves through parametric decay instability in a three-component plasma composed of electrons, protons, and α particles. At the same time, α cyclotron waves get excited via another decay instability. A pre-accelerated α particle resonates simultaneously with the two daughter waves, the SPA waves and the α cyclotron waves, and it is further accelerated perpendicular to the ambient magnetic field. The process may work in astrophysical environments where a sufficiently large temperature anisotropy of lower mass ions occurs..
10. Yamazaki, R.; Shinoda, A.; Umeda, T.; Matsukiyo, S., Mach number and plasma beta dependence of the ion temperature perpendicular to the external magnetic field in the transition region of perpendicular collisionless shocks, AIP Advances, 10.1063/1.5129067, 9, 12, 125010(1)-125010(6), 2019.12, [URL], Ion temperature anisotropy is a common feature for (quasi-)perpendicular collisionless shocks. By using two-dimensional full particle simulations, it is shown that the ion temperature component perpendicular to the shock magnetic field at the shock foot region is proportional to the square of the Alfvén Mach number divided by the plasma beta. This result is also explained by a simple analytical argument in which the reflected ions get energy from an upstream plasma flow. By comparing our analytic and numerical results, it is also confirmed that the fraction of the reflected ions hardly depends on the plasma beta and the Alfvén Mach number when the square of the Alfvén Mach number divided by the plasma beta is larger than about 20..
11. Otsuka, F.; Matsukiyo, S.; Hada, T., PIC Simulation of a quasi-parallel collisionless shock: Interaction between upstream waves and backstreaming ions, High Energy Density Physics, 10.1016/j.hedp.2019.100709, 33, 100709(1)-100709(10), 2019.11, [URL], We perform a one-dimensional full particle-in-cell (PIC) simulation of a quasi-parallel collisionless shock with the Alfvén Mach number 6.6 and a shock angle of 20 degrees between the upstream magnetic field and the shock normal direction. The backstreaming ions are self-consistently generated by reflections of the incoming ions at the shock. They generate the Alfvénic electromagnetic wave via the right-handed resonant ion-ion instability, as the ions travel toward the upstream region. The energy distribution of the backstreaming ions far upstream splits into two populations as it approaches the shock. The energy threshold of the populations is approximately the energy gained by a single specular reflection at the shock. The maximum energy of the backstreaming ions near the shock is about 10 times larger than the specularly reflected ion energy. Nonlinear phase bunches of the high-energy backstreaming ions and the background ions are found near the shock, due to the resonant and non-resonant trappings by the excited waves, respectively..
12. Oka, M.; Otsuka, F.; Matsukiyo, S.; Wilson, L. B., III; Argall, M. R.; Amano, T.; Phan, T. D.; Hoshino, M.; Le Contel, O.; Gershman, D. J.; Burch, J. L.; Torbert, R. B.; Dorelli, J. C.; Giles, B. L.; Ergun, R. E.; Russell, C. T.; Lindqvist, P. A., Electron Scattering by Low-frequency Whistler Waves at Earth’s Bow Shock, The Astrophysical Journal, 10.3847/1538-4357/ab4a81, 886, 1, 53(1)-53(11), 2019.11, [URL], 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..
13. Morita, T.; Nagashima, K.; Edamoto, M.; Tomita, K.; Sano, T.; Itadani, Y.; Kumar, R.; Ota, M.; Egashira, S.; Yamazaki, R.; Tanaka, S. J.; Tomita, S.; Tomiya, S.; Toda, H.; Miyata, I.; Kakuchi, S.; Sei, S.; Ishizaka, N.; Matsukiyo, S.; Kuramitsu, Y.; Ohira, Y.; Hoshino, M.; Sakawa, Y., Anomalous plasma acceleration in colliding high-power laser-produced plasmas, Physics of Plasmas, 10.1063/1.5100197, 26, 9, 090702(1)-090702(6), 2019.09, [URL], 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..
14. Niemiec, J.; Kobzar, O.; Amano, T.; Hoshino, M.; Matsukiyo, S.; Matsumoto, Y.; Pohl, M., Electron Acceleration at Rippled Low Mach Number Shocks in Merging Galaxy Clusters, 36th International Cosmic Ray Conference (ICRC2019), 2019.07, [URL].
15. Bolouki, N.; Sakai, K.; Huang, T. Y.; Isayama, S.; Liu, Y. L.; Peng, C. W.; Chen, C. H.; Khasanah, N.; Chu, H. H.; Moritaka, T.; Tomita, K.; Sato, Y.; Uchino, K.; Morita, T.; Matsukiyo, S.; Hara, Y.; Shimogawara, H.; Sakawa, Y.; Sakata, S.; Kojima, S.; Fujioka, S.; Shoji, Y.; Tomiya, S.; Yamazaki, R.; Koenig, M.; Kuramitsu, Y., Collective Thomson scattering measurements of electron feature using stimulated Brillouin scattering in laser-produced plasmas, High Energy Density Physics, 10.1016/j.hedp.2019.06.002, 32, 82-88, 2019.07, [URL], 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..
16. Umeda,T.; Yamazaki,R.; Ohira,Y.; Ishizaka,N.; Kakuchi,S.; Kuramitsu,Y.; Matsukiyo,S.; Miyata,I.; Morita,T.; Sakawa,Y.; Sano.T.; Sei,S.; Tanaka,S.J.; Toda,H. Tomita,S., 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, Physics of Plasmas, 10.1063/1.5079906, 26, 3, 032303(1)-032303(12), 2019.03, [URL], 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..
17. Kuramitsu,Y.; Moritaka,T.; Sakawa,Y.; Morita,T.; Sano,T.; Koenig,M.; Gregory,C.D.; Woolsey,N.; Tomita,K.; Takabe,H.; Liu,Y.L.; Chen,S.H.; Matsukiyo,S.; Hoshino,M., Magnetic reconnection driven by electron dynamics, Nature Communications, 10.1038/s41467-018-07415-3, 9, 5109(1)-5109(6), 2018.11, [URL], 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..
18. Kis,A.; Matsukiyo,S.; Otsuka,F.; Hada,T.; Lemperger, I.; Dandouras, I.; Barta, V.; Facsko, G., Effect of upstream ULF waves on the energetic ion fiffusion at the Earth's foreshock: II. Observations, The Astrophysical Journal, 10.3847/1538-4357/aad08c, 863, 136(1)-136(9), 2018.08, [URL], 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..
19. Otsuka,F.; Matsukiyo,S.,Hada,T, Effect of field-aligned beam on upstream wave excitation and particle scattering in the earth's foreshock: One-dimensional PIC simulation, 35th International Cosmic Ray Conference. 10-20 July, 2017. Bexco, Busan, Korea, Proceedings of Science, https://doi.org/10.22323/1.301.0078, 301, 78(1)-78(5), 2018.03, [URL], 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 % 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..
20. 中野谷賢, 羽田 亨, Shuichi Matsukiyo, Diffusive shock acceleration of cosmic rays from two stationary shocks, Earth, Planets and Space, 10.1186/s40623-018-0799-3, 70, 33(1)-33(6), 2018.02, [URL], 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..
21. Otsuka,F.; Matsukiyo,S.; Kis,A.; Nakanishi,K.; Hada,T., Effect of upstream ULF waves on the energetic ion fiffusion at the Earth's foreshock: I. Theory and simulation, The Astrophysical Journal, 10.3847/1538-4357/aa8363, 853, 117(1)-117(11), 2018.01, [URL], Field-aligned diffusion of energetic ions in the Earth’s foreshock is investigated by using the quasi-linear theory (QLT) and test particle simulation. Non-propagating MHD turbulence in the solar wind rest frame is assumed to be purely transverse with respect to the background field. We use a turbulence model based on a multi-power-law spectrum including an intense peak that corresponds to upstream ULF waves resonantly generated by the field-aligned beam (FAB). The presence of the ULF peak produces a concave shape of the diffusion coefficient when it is plotted versus the ion energy. The QLT including the effect of the ULF wave explains the simulation result well, when the energy density of the turbulent magnetic field is 1% of that of the background magnetic field and the power-law index of the wave spectrum is less than 2. The numerically obtained e-folding distances from 10 to 32 keV ions match with the observational values in the event discussed in the companion paper, which contains an intense ULF peak in the spectra generated by the FAB. Evolution of the power spectrum of the ULF waves when approaching the shock significantly affects the energy dependence of the e-folding distance..
22. 中野谷賢, Shuichi Matsukiyo, 羽田 亨, Christian X. Mazelle, Electromagnetic structure and electron acceleration in shock-shock interaction, The Astrophysical Journal, 10.3847/1538-4357/aa8363, 846, 113(1)-113(7), 2017.09, [URL], A shock-shock interaction is investigated by using a one-dimensional full particle-in-cell simulation. The simulation reproduces the collision of two symmetrical high Mach number quasi-perpendicular shocks. The basic structure of the shocks and ion dynamics is similar to that obtained by previous hybrid simulations. The new aspects obtained here are as follows. Electrons are already strongly accelerated before the two shocks collide through multiple reflection. The reflected electrons self-generate waves upstream between the two shocks before they collide. The waves far upstream are generated through the right-hand resonant instability with the anomalous Doppler effect. The waves generated near the shock are due to firehose instability and have much larger amplitudes than those due to the resonant instability. The high-energy electrons are efficiently scattered by the waves so that some of them gain large pitch angles. Those electrons can be easily reflected at the shock of the other side. The accelerated electrons form a power-law energy spectrum. Due to the accelerated electrons, the pressure of upstream electrons increases with time. This appears to cause the deceleration of the approaching shock speed. The accelerated electrons having sufficiently large Larmor radii are further accelerated through the similar mechanism working for ions when the two shocks are colliding..
23. Khasanah,N.; Peng,C.W.; Chen,C.H.; Huang,T.Y.; Bolouki,N.; Moritaka,T.; Hara,Y.; Shimogawara,H.; Sano,T.; Sakawa,y.; Sato,Y.; Tomita,K.; Uchino,K.; Matsukiyo,S.; Shoji,Y.; Tomita,S.; Tomiya,S.; Yamazaki,R.; Koenig,M.; Kuramitsu,Y., Spatial and temporal plasma evolutions of magnetic reconnection in laser produced plasmas, High Energy Density Physics, 10.1016/j.hedp.2017.02.004, 23, 15-19, Vol.23,15, 2017.06, [URL], Magnetic reconnection is experimentally investigated in laser produced plasmas. By irradiating a solid target with a high-power laser beam, a magnetic bubble is generated due to the Biermann effect. When two laser beams with finite focal spot displacements are utilized, two magnetic bubbles are generated, and the magnetic reconnection can take place. We measure the spatial and temporal plasma evolutions with optical diagnostics using framing camera. We observed the plasma jets, which are considered to be reconnection out flows. Spatial and temporal scales of the plasma jets are much larger than those of laser. The magnetic reconnection time has been estimated from the expansion velocity, which is consistent with the Sweet-Parker model..
24. Kuramitsu,Y.; Mizuta,A.; Sakawa,Y.; Tanji,H.; Ide,T.; Sano,T.; Koenig,M.; Ravasio,A.; Pelka,A.; Takabe,H.; Gregory,C.D.; Woolsey,N.; Moritaka,T.; Matsukiyo,S.; Matsumoto,Y.; Ohnishi,N., Time evolution of Kelvin-Helmholtz vortices associated with collisionless shocks in laser-produced plasmas, Astrophysical Journal, 10.3847/0004-637X/828/2/93, 828, 93(1)-93(10), Vol.828, 93, 2016.09, [URL], 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..
25. Kuramitsu,Y.; Ohnishi,N.; Sakawa,Y.; Morita,T.; Tanji,H.; Ide,T.; Nishio,K.; Gregory,C.D.; Waugh,J.N.; Booth,N.; Heathcote,R.; Murphy,C.; Gregori,G.; Smallcombe,J.; Barton,C.; Diziere,A.; Koenig,M.; Woolsey,N.; Matsumoto,Y.; Mizuta,A.; Sugiyama,T.; Matsukiyo,S.; Moritaka,T.; Sano,T.; Takabe,H., Model experiment of magnetic field amplification in laser-produced plasmas via the Richtmyer-Meshkov instability, Physics of Plasmas, https://doi.org/10.1063/1.4944925, 23, 032126(1)-032126(6), Vol.23, 032126, 2016.03, [URL].
26. Yoshitaka Shoji, Ryo Yamazaki, Sara Tomita, Yushiro Kawamura, Yutaka Ohira, Satoshi Tomiya, Youichi Sakawa, Takayoshi Sano, Yukiko Hara, Sarana Kondo, Hiroshi Shimogawara, Shuichi Matsukiyo, 森田 太智, 富田 健太郎, Hitoki Yoneda, Kazunori Nagamine, Yasuhiro Kuramitsu, Toseo Moritaka, Naofumi Ohnishi, Toward the generation of magnetized collisionless shocks with high-power lasers, Plasma and Fusion Research, 10.1585/pfr.11.3401031, 11, 3401031-1-3401031-3, 2016.04, [URL].
27. T. Ishikawa, Youichi Sakawa, Taichi Morita, Y. Yamaura, 蔵満康浩, Toseo Moritaka, Takayoshi Sano, R. Shimoda, KENTARO TOMITA, Kiichiro Uchino, Shuichi Matsukiyo, Akira Mizuta, Naofumi Ohnishi, R. Crowston, N. Woolsey, H. Doyle, G. Gregori, M. Koenig, C. Michaut, Thomson scattering measurement of a collimated plasma jet generated by a high-power laser system, Journal of Physics: Conference Series, 10.1088/1742-6596/688/1/012098, 688, 012098(1)-012098(5), Vol.688, 012098, 2016.04, [URL].
28. 蔵満康浩, Shuichi Matsukiyo, Shogo Isayama, D. Harada, T. Oyama, R. Fujino, Youichi Sakawa, Taichi Morita, Y. Yamaura, T. Ishikawa, Toseo Moritaka, Takayoshi Sano, KENTARO TOMITA, R. Shimoda, Y. Sato, Kiichiro Uchino, A. Pelka, R. Crowston, N. Woolsey, Spherical shock in the presence of an external magnetic field, Journal of Physics: Conference Series, 10.1088/1742-6596/688/1/012056, 688, 012056(1)-012056(5), Vol.688, 012056, 2016.04, [URL].
29. Shuichi Matsukiyo, 蔵満康浩, KENTARO TOMITA, Collective scattering of an incident monochromatic circularly polarized wave in an unmagnetized non-equilibrium plasma, Journal of Physics: Conference Series, 10.1088/1742-6596/688/1/012062, 688, 012062(1)-012062(4), Vol.688, 012062, 2016.04, [URL].
30. Shuichi Matsukiyo, Yosuke Matsumoto, Electron Acceleration at a High Beta and Low Mach Number Rippled Shock, Journal of Physics: Conference Series, 10.1088/1742-6596/642/1/012017, 642, 012017(1)-012017(7), Vol.642, 012017, 2015.09, [URL].
31. Shuichi Matsukiyo, Manfred Scholer, Simulations of pickup ion mediated quasi-perpendicular shocks: Implications for the heliospheric termination shock, Journal of Geophysical Research, 10.1002/2013JA019654, 119, 2014.04.
32. 中野谷賢, Shuichi Matsukiyo, 羽田 亨, Full particle-in-cell simulation of two colliding shocks, Proceedings of the 12th Asia Pacific Physics Conference (JPS Conference Proceedings), http://dx.doi.org/10.7566/JPSCP.1.015103, 1, 015103-1-015103-5, 2014.03, [URL].
33. Takayuki Umeda, Yoshitaka Kidani, Shuichi Matsukiyo, Ryo Yamazaki, Dynamics and microinstabilities at perpendicular collisionless shock: A comparison of large-scale two-dimensional full particle simulations with different ion to electron mass ratio, Physics of Plasmas, DOI: 10.1063/1.4863836, 21, 2, 022102-1-022102-10, vol.21, issue 2, 022102, 2014.02, [URL].
34. S. Matsukiyo, M. Scholer, Dynamics of energetic electrons in nonstationary quasi-perpendicular shocks, Journal of Geophysical Research, 10.1029/2012JA017986, 117, A11, A11105, vol.117, A11, A11105, 2012.11, [URL].
35. Takayuki Umeda, Shuichi Matsukiyo, Takanobu Amano, Yoshizumi Miyoshi, A numerical electromagnetic linear dispersion relation for Maxwellian ring-beam velocity distributions, Physics of Plasmas, DOI: 10.1063/1.4736848, 19, 7, 072107, vol.19, issue 7, 072107, 2012.07, [URL].
36. Terasawa, Toshio; Matsukiyo, Shuichi, Cyclotron Resonant Interactions in Cosmic Particle Accelerators, Space Science Reviews, 10.1007/s11214-012-9878-0, 2012.04, [URL].
37. Takayuki Umeda, Yoshitaka Kidani, Shuichi Matsukiyo, Ryo Yamazaki, Microinstabilities at perpendicular collisionless shocks: A comparison of full particle simulations with different ion to electron mass ratio, Physics of Plasmas, DOI: 10.1063/1.3703319, 19, 4, 042109, vol.19, issue 4, 042109, 2012.04, [URL].
38. Takayuki Umeda, Yoshitaka Kidani, Shuichi Matsukiyo, Ryo Yamazaki, Modified two-stream instability at perpendicular collisionless shocks: Full particle simulations, Journal of Geophysical Research, 10.1029/2011JA017182, 117, A3, A03206, vol.117, Issue A3, CiteID A03206, 2012.03, [URL].
39. Shuichi Matsukiyo, Yutaka Ohira, Ryo Yamazaki, Takayuki Umeda, Relativistic Electron Shock Drift Acceleration in Low Mach Number Galaxy Cluster Shocks, Astrophysical Journal, 10.1088/0004-637X/742/1/47, 742, Issue 1, article id. 47, vol.742, article id. 47, 2011.11, [URL].
40. S. Matsukiyo, M. Scholer, Microstructure of the heliospheric termination shock: Full particle electrodynamic simulations, Journal of Geophysical Research, 10.1029/2011JA016563, 116, A8, A08106, vol.116, A8, A08106, 2011.08, [URL].
41. Horia Comisel, Manfred Scholer, Jan Soucek, Shuichi Matsukiyo, Non-stationarity of the quasi-perpendicular bow shock: comparison between Cluster observations and simulations, Annales Geophysicae, 10.5194/angeo-29-263-2011, 29, Issue 2, 263-274, vol.29, Issue 2, pp.263-274, 2011.02, [URL].
42. Umeda, T., Y. Kidani, M. Yamao, S. Matsukiyo, R. Yamazaki, On the reformation at quasi- and exactly perpendicular shocks: Full particle-in-cell simulations, Journal of Geophysical Research, 10.1029/2010JA015458, 115, A10250, vol.115, A10250, 2010.10, [URL].
43. Shuichi Matsukiyo, Mach number dependence of electron heating in high Mach number quasiperpendicular shocks, Physics of Plasmas, 10.1063/1.3372137, 17, 4, 042901, Vol.17, Issue 4, pp.042901, 2010.04, [URL].
44. Reflected electrons upstream of collisionless shocks.
45. Shuichi Matsukiyo, Tohru Hada, Relativisitic particle acceleration in developing Alfven turbulence, Astrophysical Journal, 10.1088/0004-637X/692/2/1004, 692, Issue 2, 1004-1012, vol.692, pp.1004-1012, 2009.02, [URL].
46. Nariyuki, Y.; Matsukiyo, S.; Hada, T., Parametric instabilities of large-amplitude parallel propagating Alfvén waves: 2D PIC simulation, New Journal of Physics, 10.1088/1367-2630/10/8/083004, 10, Issue 8, 083004, Volume 10, Issue 8, pp. 083004
DOI:10.1088/1367-2630/10/8/083004, 2008.08, [URL].
47. Terasawa, T.; Hada, T.; Matsukiyo, S.; Oka, M.; Bamba, A.; Yamazaki, R., Shock Modification by Cosmic-Ray-Excited Turbulences, Progress of Theoretical Physics Supplement, 169, 146-149, No. 169, pp. 146-149, 2007.06, [URL].
48. Shuichi Matsukiyo, Manfred Scholer, Shock angle dependence of nonstationary behaviour of quasi-perpendicular shocks, IRCS International workshop on Shock Formation under Extreme Environments in the Universe, 2007.03.
49. Shuichi Matsukiyo, Manfred Scholer, David Burgess, Pickup protons at quasi-perpendicular shocks: full particle electrodynamic simulations, Annales Geophysicae, 25, Issue 1, 283-291, vol.25, Issue 1, pp.283-291, 2007.01, [URL].
50. Shuichi Matsukiyo, Manfred Scholer, On reformation of quasi-perpendicular collisionless shocks, Advances in Space Research, 10.1016/j.asr.2004.08.012, 38, Issue 1, 57-63, vol. 38, Issue 1, pp.57-63, 2006.09, [URL].
51. Shuichi Matsukiyo, Manfred Scholer, On microinstabilities in the foot of high Mach number perpendicular shocks, Journal of Geophysical Research, 10.1029/2005JA011409, 111, Issue A6, CiteID A06104, vol. 111, Issue A6, CiteID A06104, DOI 10.1029/2005JA011409, 2006.06, [URL].
52. Munoz,V.; Hada,T.; Matsukiyo,S., Kinetic effects on the parametric decays of Alfvén waves in relativistic pair plasmas, Earth, Planets and Space, 58, 1213-1217, Vol.58, pp.1213-1217, 2006.09, [URL].
53. Manfred Scholer, Shuichi Matsukiyo, On Kinetic Structure of Quasi-Perpendicular Collisionless Shocks, THE PHYSICS OF COLLISIONLESS SHOCKS: 4th Annual IGPP International Astrophysics Conference. AIP Conference Proceedings, 10.1063/1.2032669, 781, 22-26, Volume 781, pp. 22-26, 2005.08.
54. Shuichi Matsukiyo, Manfred Scholer, Modified two-stream instability in a high Mach number quasi-perpendicular shock front, Proceedings of the 7th ISSS (International School/Symposium for Space Simulations), pp. 313-314, 2005.03.
55. Tohru Hada, Shuichi Matsukiyo, Masahiro Ikeda, Victor Munoz, Dispersion relation and nonlinear evolution of large amplitude relativistic Alfven waves, プラズマ科学シンポジウム2005 / 第22回プラズマプロセシング研究会(PSS-2005/SPP-22)プロシーディングス, 2005.01.
56. Shuichi Matsukiyo, Manfred Scholer, Structure of high Mach number quasi-perpendicular shocks and wave-particle interactions in their transition region, プラズマ科学シンポジウム2005 / 第22回プラズマプロセシング研究会(PSS-2005/SPP-22)プロシーディングス, 2005.01.
57. Tohru Hada, Shuichi Matsukiyo, Victor Munoz, Disperson relation of finite amplitude Alfven wave in a relativistic electron- positron plasma, 12th International Congress on Plasma Physics, eprint arXiv:physics/0410203, 2004.10.
58. Manfred Scholer, Shuichi Matsukiyo, Nonstationarity of quasi-perpendicular shocks: a comparison of full particle simulations with different ion to electron mass ratio, Annales Geophysicae, 22, Issue 7, 2345-2353, Vol.22, pp.2345-2353, 2004.07, [URL].
59. Shuichi Matsukiyo, Rudolf Treumann, Manfred Scholer, Coherent waveforms in the auroral upward current region, Journal of Geophysical Research, 10.1029/2004JA010477, 109, Issue A6, CiteID A06212, Volume 109, Issue A6, CiteID A06212, 2004.06, [URL].
60. Shuichi Matsukiyo, Manfred Scholer, Modified two-stream instability in the foot of high Mach number quasi-perpendicular shocks, Journal of Geophysical Research, 10.1029/2003JA010080, 108, Issue A12, SMP 19-1, Volume 108, Issue A12, pp. SMP 19-1, CiteID 1459, DOI 10.1029/2003JA010080, 2003.12, [URL].
61. Shuichi Matsukiyo, Tohru Hada, Parametric instabilities of circularly polarized Alfvén waves in a relativistic electron-positron plasma, Physical Review E,, 10.1103/PhysRevE.67.046406, 67, Issue 4, id. 046406, vol. 67, Issue 4, id. 046406, 2003.04, [URL].
62. Manfred Scholer, Iku Shinohara, Shuichi Matsukiyo, Quasi-perpendicular shocks: Length scale of the cross-shock potential, shock reformation, and implication for shock surfing, Journal of Geophysical Research, 10.1029/2002JA009515, 108, Issue A1, SSH 4-1, Volume 108, Issue A1, pp. SSH 4-1, CiteID 1014, DOI 10.1029/2002JA009515, 2003.01, [URL].
63. Shuichi Matsukiyo, Tohru Hada, Long time evolution of electromagnetic waves driven by the relativistic ring distribution, Engineering Sci. Rep., vol.22, No.4, pp. 375 – 384, 2001.01, [URL].
64. , [URL].
65. Shuichi Matsukiyo, Tohru Hada, Nonlinear evolution of electromagnetic waves driven by the relativistic ring distribution, Physics of Plasmas, 10.1063/1.1431593, 9, Issue 2, 649-661, Volume 9, Issue 2, February 2002, pp.649-661, 2002.02, [URL].
66. Shuichi Matsukiyo, Tohru Hada, Mitsuhiro Nambu, Jun-Ichi Sakai, Comparison between the Landau and Cyclotron Resonances in the Electron Beam-Plasma Interactions, Journal of Physical Society of Japan, 10.1143/JPSJ.68.1049, 68, Issue 3, 1049-1054, Vol.68, Issue 3, pp.1049-1054, 1999.03, [URL].
67. Shuichi Matsukiyo, Mitsuhiro Nambu, Tohru Hada, Jun-ichi Sakai, Torsten Neubert, Simulation study on generation of waves from electron beam by the Cherenkov maser, Proceedings of The Fifth International School/Symposium for Space Simulations, 1997.03.