| 長谷川 真（はせがわ まこと） | データ更新日：2024.04.02 |
准教授 ／
応用力学研究所
核融合力学部門
| 1. | 長谷川 真，井戸 毅，花田 和明, 出射 浩, 池添 竜也, 恩地 拓己, 木下 稔基, トカマクプラズマ位置形状の機械学習を用いた高速同定, 令和６年電気学会全国大会, 2024.03, [URL]. |
| 2. | 長谷川 真, QUEST Group, クエストのプラズマ制御システムと機械学習によるプラズマ形状の高速同定, 第１９回クエスト研究会, 2024.03, [URL]. |
| 3. | Makoto Hasegawa, and QUEST Group, Plasma control system of QUEST and fast plasma shape recognition with Machine Learning, 12th QUEST Workshotp "RF startup and sustainment in Spherical Tokamak", 2024.02, [URL]. |
| 4. | 長谷川 真, and QUESTグループ, QUESTの長時間運転における計測と制御, 第25回若手科学者によるプラズマ研究会, 2023.03, [URL]. |
| 5. | 長谷川 真, and QUESTグループ, 共同利用装置QUESTの実験環境および実験データについて, 第１８回クエスト研究会, 2022.09, [URL]. |
| 6. | 長谷川 真, QUESTグループ, 実験装置の概要(II) QUEST , 先進トカマク研究会, 2022.09. |
| 7. | Makoto Hasegawa, Introduction of large plasma experimental device QUEST, Sakura Science for HFUT, 2021.11. |
| 8. | Makoto Hasegawa, Long-time operation with high temperature wall ( |
| 9. | 長谷川 真, QUESTにおける高温壁( |
| 10. | M. Hasegawa, K. Hanada, N. Yoshida, H. Idei, T. Ido, Y. Nagashima, R. Ikezoe, T. Onchi, K. Kuroda, S. Kawasaki, A. Higashijima, T. Nagata, S. Shimabukuro, K. Nakamura, QUESTにおける高温壁( |
| 11. | Makoto Hasegawa, Daisuke Sakurai, Aki Higashijima, Ichiro Niiya, Keiji Matsushima, Kazuaki Hanada, Hiroshi Idei, Takeshi Ido, Ryuya Ikezoe, Takumi Onchi, Kengo Kuroda, Towards Automated Gas Leak Detection through Cluster Analysis of Mass Spectrometer Data, 13th Technical Meeting on Plasma Control Systems, Data Management and Remote Experiments in Fusion Research, 2021.07, In order to generate high-performance plasma for future fusion power generation, it is desirable to keep high quality vacuum during experiment. Mass spectrometer is commonly used to monitor the vacuum quality and to record the amount of atoms and molecules in the vacuum vessel. Leak is the most serious accident to avoid that can nullify an experiment and even harm researchers. Detecting leaks are ever more important since it can be easily overlooked, e.g., when the deterioration in the vacuum degree is modest. This forces the researcher to carefully observe the vacuum and mass spectrometer data. This article presents a way to suggest potential leaks in the vacuum vessel by analyzing mass spectrometer data. This is done by utilizing the Euclidean distance between composition ratios at different times for the clustering using the daily composition ratio. We show that our cluster analysis is an effective way of separating these two cases, which results in a semi-automatic determination of leaks is more efficient than the current norm, which is to check many measures to find a small abnormality in the data manually. We plan further model improvements for long-term evaluation.. |
| 12. | M. Hasegawa, K. Hanada, N. Yoshida, H. Idei, T. Ido, Y. Nagashima, R. Ikezoe, T. Onchi, K. Kuroda, S. Kawasaki, A. Higashi, T. Nagata, S. Shimabukuro, K. Nakamura, Extension of Operation Area for Steady State Operation on QUEST by Integrated Control with Hot Walls, 9th International Workshop, RIAM 2021, 2021.01, [URL], Steady state operation of magnetically confined plasmas has been studied on the Q-shu University Experiment with steady state spherical tokamak (QUEST). In future power plants, to increase power generation efficiency by heat exchange, its operation temperature will be around 773 K, and it is desirable to realize steady state operation. However, the uncontrollable increase in plasma density, which tends to occur with high temperature walls, prevents the realization of them. They are definitely relating to plasma-wall interaction (PWI) and particle balance, and more detailed studies are required. QUEST has all-metal plasma facing walls (PFWs) and its temperature can be controlled with resistive heaters and cooling water. The typical operating temperature range on the PFWs is between room temperature and less than 773 K. To control the temperature on the PFWs, hot walls and radiation shields have been installed inside the vacuum vessel on QUEST. The radiation shields prevent the outflow of heat so that the hot wall, namely PFW, can be maintained at high temperatures. Recently, tokamak plasma discharges longer than 6 h were achieved with full non-inductive electron cyclotron current drive (ECCD) using a RF source of 8.2 GHz. The input RF power was in the range of 20 kW, and the wall temperature was higher than 423 K. In these shots, particle fueling were properly feedback-controlled to keep plasma influx constant by referring Ha emission. However, in typical long discharge, the fueling gradually decreased and finally stopped due to a so-called “wall saturation”. This indicates the unknown particle sources is significantly affecting in the particle balance. On the other hand, when the cooling water for the hot walls was circulated under these situations, the particle fueling was observed to restart spontaneously. This also indicates that the integrated control including particle fueling and temperature of PFWs is important and this realization contributes expansion of operation area toward steady state operations.. |
| 13. | M. Hasegawa, K. Hanada, N. Yoshida, H. Idei, T. Ido, Y. Nagashima, R. Ikezoe, T. Onchi, K. Kuroda, S. Kawasaki, A. Higashi, T. Nagata, S. Shimabukuro, K. Nakamura, Extension of Operation Area for Steady State Operation on QUEST by Integrated Control with Hot Walls, The 29th International Toki Conference on Plasma and Fusion Research (ITC29), 2021.01, [URL], Steady state operation of magnetically confined plasmas has been studied on the Q-shu University Experiment with steady state spherical tokamak (QUEST). In future power plants, to increase power generation efficiency by heat exchange, its operation temperature will be around 773 K, and it is desirable to realize steady state operation. However, the uncontrollable increase in plasma density, which tends to occur with high temperature walls, prevents the realization of them. They are definitely relating to plasma-wall interaction (PWI) and particle balance, and more detailed studies are required. QUEST has all-metal plasma facing walls (PFWs) and its temperature can be controlled with resistive heaters and cooling water. The typical operating temperature range on the PFWs is between room temperature and less than 773 K. To control the temperature on the PFWs, hot walls and radiation shields have been installed inside the vacuum vessel on QUEST. The radiation shields prevent the outflow of heat so that the hot wall, namely PFW, can be maintained at high temperatures. Recently, tokamak plasma discharges longer than 6 h were achieved with full non-inductive electron cyclotron current drive (ECCD) using a RF source of 8.2 GHz. The input RF power was in the range of 20 kW, and the wall temperature was higher than 423 K. In these shots, particle fueling were properly feedback-controlled to keep plasma influx constant by referring Ha emission. However, in typical long discharge, the fueling gradually decreased and finally stopped due to a so-called “wall saturation”. This indicates the unknown particle sources is significantly affecting in the particle balance. On the other hand, when the cooling water for the hot walls was circulated under these situations, the particle fueling was observed to restart spontaneously. This also indicates that the integrated control including particle fueling and temperature of PFWs is important and this realization contributes expansion of operation area toward steady state operations.. |
| 14. | 長谷川真、QUESTグループ, QUESTで実装している幾つかの制御手法とそのシステム, 平衡再構成のための計測技術と解析手法, 2018.07. |
| 15. | Makoto Hasegawa, Introduction of experimental system on large plasma experimental device QUEST, さくらサイエンスプラン, 2017.12, ●Introduction of QUEST ・History of long duration discharges ●Exp. system including plasma control system on QUEST ●Usage of FPGA as software-defined technology ●Information sharing with Ethernet for coordinated operation ●Summary. |
| 16. | M. Hasegawa, K. Hanada, N. Yoshida, A. Kuzmin, H. Zushi, K. Nakamura, A. Fujisawa, H. Idei, Y. Nagashima, O. Watanabe, T. Onchi, K. Kuroda, H. Watanabe, K. Tokunaga, A. Higashijima, S. Kawasaki, and T. Nagata, Efforts toward Steady State Operation in Long Duration Discharges with the Control of Hot Wall Temperature on QUEST, 1st Asia-Pacific Conference on Plasma Physics, 2017.09, Efforts toward Steady State Operation in Long Duration Discharges with the Control of Hot Wall Temperature on QUEST M. Hasegawa1, K. Hanada1, N. Yoshida1, A. Kuzmin1, H. Zushi1, K. Nakamura1, A. Fujisawa1, H. Idei1, Y. Nagashima1, O. Watanabe1, T. Onchi1, H. Watanabe1, K. Tokunaga1, A. Higashijima1, S. Kawasaki1, and T. Nagata1 1 RIAM, Kyushu University, Japan Achievement of steady state operation (SSO) of magnetic fusion devices is one of important issues for fusion research. Fully non-inductive plasma start-up and its maintenance up to 1h55min was successfully achieved on QUEST with a microwave of 8.2GHz, 40kW and well-controlled gas fueling and plasma-facing wall (PFW) temperature of 373K. The gas fueling is feedback controlled to keep constant in H signal, which can be an indicator of in-coming H flux to plasma facing materials (PFMs). On QUEST, the hot wall, which can be actively heated by electrical heater, was installed inside the vacuum vessel in 2014 autumn/winter (A/W) campaign, and the plasma can be sustained with high temperature PFW to investigate particle balance such as fuel recycling and wall pumping properties. Thermal insulators are installed between hot wall and vacuum vessel wall to keep the temperature of vacuum vessel wall below 423K for the protection of various diagnostics and plasma-heating devices. The function of active cooling of hot wall with cooling water channels will be installed in 2017 spring/summer (S/S) campaign. The plasma-wall interaction (PWI) is an important subject when considering SSO, and is a wide-range issue because the matters such as material science and the plasma science are linked each other complicatedly. In these matters, especially, power balance and particle balance play important roles against SSO. The power balance in long duration discharges was sufficiently investigated in TRIAM-1M, which has the world record of plasma duration on tokamaks for more than 5h16min [1]. During the long plasma discharge, all of the temperatures of PFMs are saturated and kept constant on TRIAM-1M. The power balance on QUEST is also investigated before 2014, in which the hot wall had been installed. Approximately 70%-90% of the injected power could be detected by calorimetric measurements of PFMs, and about half of the injected power was deposited on the vessel wall [2]. The total particle balance on QUEST is estimated experimentally [3]. The time evolution of wall-pumping rate is evaluated as the difference between injected and evacuated H2 flux, which are derived from the flowmeter installed on gas fueling system and a quadrupole mass analyzer (QMS) installed on the bottom of the vessel, respectively. Absolute values of them are calibrated with consideration of the pressure and volume of gas fueling line and the relationship between flowmeter and QMS signal with the situation of no plasma. The wall-stored H can be obtained by time-integration of wall-pumping rate with setting the initial integrated value at zero. On the QUEST, the wall kept at higher temperature is rather active, and almost all stored H particles are released from the wall during the intervals of plasma discharges. In the long duration discharges, the wall pumping occurs in the initial phase, and its rate gradually decrease. Finally, the wall-pumping rate becomes zero, and the wall saturation occurs. This tendency is likely to occur faster when its wall temperature is higher. To express this tendency, a wall model with hydrogen barrier (HB) which is formed around boundary between the deposition layer and the substrate was proposed [4]. In this model, the time derivative of the number of H dissolved in wall (dHW/dt) is proportional to the square of HW, when the number of H trapped in defects (HT) can be negligible. The parabolic relation between dHW/dt and HW is clearly observed in low HW experimentally, and the given curves with this model is well-fitted to the experimental observation. References [1] H.Zushi, et al, Steady-state tokamak operation, ITB transition and sustainment and ECCD experiments in TRIAM-1M, Nuclear Fusion, 45 (2005) S142-S156 [2] K.Hanada, et al, Power Balance Estimation in Long Duration Discharge on QUEST, Plasma Science and Technology, 18 (2016) 1069-1075. [3] K. Hanada, et al, Investigation of hydrogen recycling property and its control with hot wall in long duration discharges on QUEST, Nuclear Fusion, (2017) to be published. [4] K. Hanada, et al, Particle balance in long duration RF driven plasmas on QUEST, Journal of Nuclear Materials, 463 (2015) 1084-1086.. |
| 17. | 長谷川真, QUESTグループ, QUEST定常プラズマの統合制御, 第１４回QUEST研究会, 2017.07, ●QUESTにおける制御システム ●長時間用プラズマ同定と制御 ●粒子供給フィードバック制御 ●高温壁の温度制御とその他 ●まとめ. |
| 18. | 長谷川真, QUESTグループ, QUESTにおける定常実験に向けた制御, RIAMフォーラム２０１７, 2017.06, QUESTにおける定常プラズマ実験に向けた制御 核融合力学部門 プラズマ表面相互作用分野 長谷川真 トカマク装置など磁場閉じ込め式核融合装置において、統合的にプラズマを制御して定常運転を実現することは非常に重要な課題である。QUEST装置では、この課題解決に精力的に取り組んでおり、温度を制御することができる高温壁をプラズマ対向壁として有していることが装置の特徴の一つとして挙げられる。定常運転では、プラズマ対向壁の温度が非常に大きな役割を持ち、たとえば２００℃の壁の温度でのプラズマ放電においては、壁の粒子吸蔵量が増えてくると、１２０℃の場合に比べて壁排気量が下がることが実験的に示されている[1]。現在までにQUEST装置では壁の温度を１２０℃に保ったまま、４０kW程度の加熱入力パワーで１時間５５分に及ぶ長時間放電を実現しているが、今後更にプラズマの加熱入力パワーを増やして、主プラズマが高密度、高温度の領域においても本課題に取り組む予定である。 QUESTの高温壁には、壁の温度を高温に保つためのシースヒーターが内蔵されており、シーケンサーを用いて壁の温度をモニターしつつシースヒーターの消費電力を調整して温度をフィードバック制御する加熱システムが２０１４年に実装されている。一方、プラズマの加熱入力パワーが増えて壁への熱入力が増えてくると、加熱システムは、温度を一定に保とうとした場合、ヒーターの消費電力を下げてき、遂にはゼロにするが、更にプラズマの加熱入力パワーが増える場合には、逆に冷却する機構が必要になる。この冷却に求められる能力として、数十kW程度を見込んでおり、空気冷却では冷却能力が足りず、直接接触する水冷却では過大になると予想されることから、伝熱板を介して冷却管をパネルに接触させる間接冷却の機構が採用されている。本方式の実際の冷却能力等は今後調査していくことになるが、この冷却では電動バルブを開閉することで、冷却の有無を調節する。この調節には加熱システムや中央制御システム、またプラズマ制御システムなど、各機器間の連係動作が必要になる。講演では、これら加熱・冷却システムの紹介や、プラズマを長時間維持するための、いくつかの取り組みについて紹介する。 [1] 26th IAEA Fusion Energy Conference, EX/P4-49, K. Hanada, et. al.. |
| 19. | Makoto Hasegawa, and QUEST group, Modifications of Plasma Control System and Central Control System for Integrated Control of Long Plasma Sustainment on QUEST, 11th IAEA Technical Meeting (TM) on the Control, Data acquisition and Remote Participation for Fusion Research, 2017.05, [URL], Modifications of Plasma Control System and Central Control System for Integrated Control of Long Plasma Sustainment on QUEST Makoto Hasegawa1, Kazuo Nakamura1, Kazuaki Hanada1, Shoji Kawasaki1, Arseniy Kuzmin1, Hiroshi Idei1, Kazutoshi Tokunaga1, Yoshihiko Nagashima1, Takumi Onchi1, Kengoh Kuroda1, Osamu Watanabe1, Aki Higashijima1, and Takahiro Nagata1 1Research Institute for Applied Mechanics, Kyushu University, Kasuga, Fukuoka, Japan hasegawa@triam.kyushu-u.ac.jp, nakamura@triam.kyushu-u.ac.jp, hanada@triam.kyushu-u.ac.jp, kawasaki@triam.kyushu-u.ac.jp, kuzmin@triam.kyushu-u.ac.jp, idei@triam.kyushu-u.ac.jp, tokunaga@riam.kyushu-u.ac.jp, nagashima@triam.kyushu-u.ac.jp, onchi@triam.kyushu-u.ac.jp, kuroda@triam.kyushu-u.ac.jp, rwata@riam.kyushu-u.ac.jp, higashi@triam.kyushu-u.ac.jp, nagata@triam.kyushu-u.ac.jp Achievement of steady state operation (SSO) is one of important issues for future magnetic fusion devices. The world record of plasma duration on tokamaks for more than 5h16min was achieved in TRIAM-1M [1], where particle balance and power balance are investigated. On QUEST, which is a middle sized spherical tokamak installed on the same place after the closing of TRIAM-1M experiments, these issues are also vigorously investigated, and the fully non-inductive plasma start-up and its maintenance up to 1h55min was successfully achieved [2] with a microwave of 8.2 GHz, 40 kW and well-controlled gas fueling and plasma facing wall (PFW) temperature of 373 K. On QUEST, the hot wall which can be actively heated by electrical heaters was installed inside vacuum vessel in 2014, and the plasma discharge is sustained with high temperature PFW to investigate particle balance such as wall pumping properties. The function of active cooling for hot wall with the cooling water will be installed in 2017 spring. These controls of heating with electrical heaters and cooling with cooling water will be managed by the central control system and its peripheral subsystems with the coordination of them. On the other hand, the gas fueling during plasma discharge is feed-back controlled with referring to the signal level of H which is an indicator of in-coming H flux to PFWs. This control is managed by a Proportional-Integral-Differential (PID) control on the plasma control system using a mass-flow controller. The modifications and coordination of these control systems for long discharges are introduced. 1. H.Zushi, et al, “Steady-state tokamak operation, ITB transition and sustainment and ECCD experiments in TRIAM-1M”, Nuclear Fusion, 45 (2005) S142-S156. 2. K. Hanada, et al, Investigation of hydrogen recycling property and its control with hot wall in long duration discharges on QUEST, Nuclear Fusion, (2017) to be published.. |
| 20. | 長谷川真, QUESTにおける制御システムの現状紹介と展望, 第１３回QUEST研究会, 2017.02, ●QUESTにおける制御システム ●プラズマ制御システムの紹介 ・構成、仕様、機能など ・FPGAの使用例 ●中央制御システムの紹介 ・構成、現状の課題など ・システムへの実装例の紹介 ●まとめ. |
| 21. | 長谷川真, プラズマ境界力学実験装置QUESTにおけるFPGA利用の現状紹介, 核融合・加速器科学分野合同計測技術ワークショップ, 2016.10, [URL], QUEST装置の紹介 LabVIEW言語でのFPGA開発 FPGAの利用例 TFコイルの電気抵抗値監視 磁気計測 プラズマの電子密度計測 トリガー遅延分配器 まとめ. |
| 22. | Makoto Hasegawa, Integrated control system on spherical tokamaks, 4th A3 Foresight Summer School and Workshop on Spherical Torus (ST), 2016.08. |
| 23. | Makoto Hasegawa, Kazuo Nakamura, hideki zushi, kazuaki hanada, Akihide Fujisawa, KAZUTOSHI TOKUNAGA, Hiroshi Idei, Yoshihiko Nagashima, Aki Higashijima, Shoji Kawasaki, Hisatoshi Nakashima, Aleksandrovich Arseniy Kuzmin, Takumi Onchi, Osamu Watanabe, Kishore Mishra, Real-time identification of plasma current and its position with hall sensors for long-pulse operation on QUEST, 8th IAEA Technical Meeting on "Steady State Operation of Magnetic Fusion Devices", 2015.05, [URL], For long-pulse operation, the control of plasma current and its position is important to manage the heat loads, particle flux, and so on. Thus, the plasma current and its position have to be identified correctly during a long plasma discharge in real time. The plasma current and its position are usually calculated with signals of a rogowski coil sensor, magnetic flux loop sensors, and magnetic pick-up coil sensors. In order to calculate with these signals, the time-integrations of raw signals with electrical circuits or numerical calculations are required. However, these time-integrations cause drift errors which become larger according to the duration of the plasma discharge. And, this disturbs the correct identification and the control of a long-pulse plasma discharge. We propose the use of hall sensors for the long-pulse operation. A hall sensor does not require time-integration, and does not cause the drift error. On QUEST, several hall sensors are installed on the outside of the vacuum vessel. Although the quick behavior of plasma cannot be sensed with hall sensors because of eddy current effects, this enables high-accuracy measurements with the static environment of no plasma, no RF, and no vacuum. This also enables the repair or replacement of hall sensors without a vacuum purge. The plasma current and its position are identified in real time with these hall sensor signals. The plasma position and current are calculated by the evaluation of intensity ratios and intensities itself, respectively. . |
| 24. | Makoto Hasegawa, Kazuo Nakamura, hideki zushi, kazuaki hanada, Akihide Fujisawa, KAZUTOSHI TOKUNAGA, Hiroshi Idei, Yoshihiko Nagashima, Shoji Kawasaki, Hisatoshi Nakashima, Aki Higashijima, Current Status and Prospect of Plasma Control System for Steady-state Operation on QUEST, 10th IAEA Technical Meeting on Control, Data Acquisition and Remote Participation for Fusion Research, 2015.04, [URL], Plasma control system (PCS) on QUEST has been developed for the achievement of the steady-state sustainment of tokamak plasma. QUEST is a spherical tokamak [1], on which high temperature all metal vessel wall up to 500 K is planned for the steady-state operation under unity recycling ratio. Achievement of steady-state operation in tokamak plasma is one of a key issue to realize cost-effective fusion power plants. In the aim of this, many kind of controls are required such as plasma position and its shape control, particle balance control, and heat load control. Current status and prospect of PCS for steady-state operation on QUEST are described. For the control of plasma position and its shape, these parameters have to be identified in real time and steadily. Though magnetic sensors of rogowski coils, pick-up coils, and flux loops are usually used for this identification, these sensors are not suitable for the long time measurements because drift error induced by time integration occurs. On QUEST, in addition to these sensors, hall sensors are used, which are suitable for the long time measurement because of no drift errors. Furthermore, hall sensors can be expected to have an ease of maintenance and high accuracy because these are located on the outside of vacuum vessel wall where is less noisy environment compared to the inside one. The plasma current and position are calculated with just hall sensor signals, assuming the plasma as a filament current located on the inside of vacuum vessel. In this procedure, the plasma position and plasma current are evaluated with ratios and intensities of hall sensor signals, respectively. In addition to this, plasma shape is also evaluated in real time with a shape identification method [2]. These procedures are applicable to the control of plasma position and its shape for steady-state operation. For the control of particle balance, a fueling feed-back control is implemented, which is referring Ha signals instead of plasma density. The fueling gas is puffed when an actual Ha signal intensity is lower the target intensity, and the actual signal gradually comes close to the target signal with a setting of the pulse prohibited duration. The actual Ha signal is well controlled with this method on over 10 minutes plasma discharge. Other several approaches such as a distributing system for steady-state operation will be discussed. 1. K. Hanada, K. Sato, H. Zushi, K. Nakamura, M. Sakamoto, H. Idei, et al., “Steady-State Operation Scenario and the First Experimental Result on QUEST”, Plasma and Fusion Research, 5, S1007 (2010). 2. M. Hasegawa, K. Nakamura, H. Zushi, K. Hanada, a. Fujisawa, K. Matsuoka, et al., “Development of plasma control system for divertor configuration on QUEST”, Fusion Engineering and Design, 88, 1074–1077 (2013). . |
| 25. | 長谷川 真, プラズマ統合制御に向けた制御システムの開発, QUEST研究会, 2015.03, QUEST装置における制御システムの現状と展望の紹介. |
| 26. | Makoto Hasegawa, Kazuo Nakamura, hideki zushi, kazuaki hanada, Akihide Fujisawa, Osamu Mitarai, KAZUTOSHI TOKUNAGA, Hiroshi Idei, Yoshihiko Nagashima, Shoji Kawasaki, Hisatoshi Nakashima, Aki Higashijima, Development of high performance control system by decentralization with reflective memory on QUEST, 28th Symposium on Fusion Technology, 2014.10, [URL], Plasma control systems for tokamak plasmas are required to make control signals in real-time with simultaneously acquiring various data and calculating meaningful physical quantities. Since the physical quantities and the control signals have relationship with each other, a centralized control system is principally desirable for the grasp of these parameters. However, the computational loads on the CPU of plasma control workstation (WS) become too large to build a highly integrated control system, because it makes difficult to execute in real-time. In actual, the CPU utilization of the WS for the spherical tokamak QUEST becomes almost full. We propose to develop a decentralized control system. In this system, each control system has a reflective memory connected to each other with optical fibers, and shares various data via reflective memory. The good point of this system is to increase the CPU resource. Furthermore, the electrical insulation is ensured spontaneously. On the other hand, the synchronization accuracy between each system may become worse. The GE cPCI-5565PIORC of National Instruments Corporation is used as the reflective memory, which has 256 Mbytes memory and 170Mbyte/sec transfer rate. The most popular data type to share is double-precision real type (DBL) which needs 8 bytes to represent. The actual data read or write time is measured. Especially, within the period of 4 kHz which is the period of WS, more than 1000 to 2000 DBLs can be read or write. This means about 50 Mbytes/sec transfer rate for the one directional data sharing. For the bidirectional data sharing, each system has to repeat the read-write procedure. This would take more time. In the presentation, we will introduce the actual implementation of the reflective memory to the decentralized control system and its performance.. |
| 27. | Makoto Hasegawa, Kazuo Nakamura, Hideki Zushi, Kazuaki Hanada, Akihide Fujisawa, Keisuke Matsuoka, Hiroshi Idei, Yoshihiko Nagashima, Kazutoshi Tokunaga, Shoji Kawasaki, Hisatoshi Nakashima, Aki Higashijima, Development of plasma control system for steady state operation on QUEST, 9th Asia Plasma and Fusion Association Conference, 2013.11, [URL], A long time plasma sustainment is an important issue for the future nuclear fusion plasma. In QUEST (Q-shu university experiment with steady-state spherical tokamak), a steady state operation is also one of project objectives. Thus, the long time identification and its control of the plasma position and its shape are important for the steady state operation. However, the long time identification is difficult, as long as the integrated magnetic signals such as magnetic fluxes or magnetic fields are used because the integration errors, namely, drift errors occur and prevent the accurate identification. The WS is composed of PXI systems of the National Instruments Corporation, which contains a controller module (2.26 GHz Intel Core 2 Quad processor, memory: 2 GBytes) based on a real-time operating system, one DIO module (16-channel digital input and output), and six FPGA modules (eight-channel analog input and output in each module). In the WS, the several tasks can be performed in parallel because a multi-quad-core processor is used in the controller module. One task is for the control of a DIO module and FPGA modules. Another task, referred to as a main loop, is for the calculation of control signals by the acquired data. These two tasks are performed at 4 kHz. In addition, the real-time equilibrium calculation and the plasma image analysis are executed in parallel on other cores, respectively. The calculation period of the image analysis will be several seconds. That is sufficient to correct the drifts of magnetic fluxes. In this presentation, the development status of this control system will be introduced. . |
| 28. | 長谷川 真, Development of real-time equilibrium control system on QUEST, Workshop on QUEST and Related ST RF Startup and Sustainment Plasma Research, 2013.02. |
| 29. | 長谷川 真, 御手洗 修, 中村 一男, QUESTにおけるリアルタイム平衡計算とその制御, 平成２４年度双方向型共同研究成果報告会, 2013.01, [URL], リアルタイム用平衡計算コードの開発を行った。本コードの1回の計算時間はメッシュ数30×48の場合において2msec以内に収まると予想される。今後、この平衡計算コードの収束性や妥当性を検証するために、リミター配位やダイバータ配位など幾つかの放電パターンに対して計算を行い、実験データ及び他の平衡計算コードとの比較等を行うなどして、より詳細に吟味し、QUESTの制御システムに実装していく予定である。また、制御においては、現状はプラズマ内側エッジ位置のみの制御であるので、形状制御と呼ぶに十分な制御可能個所の個数を増やす予定である。また、プラズマ形状だけでなく、ストライクポイント等のリアルタイム同定を行い、熱負荷制御等に資する予定である。. |
| 30. | Makoto Hasegawa, Kazuo Nakamura, hideki zushi, kazuaki hanada, Akihide Fujisawa, Keisuke Matsuoka, Osamu Mitarai, Hiroshi Idei, Yoshihiko Nagashima, Kazutoshi Tokunaga, Shoji Kawasaki, Hisatoshi Nakashima, Aki Higashijima, Development of plasma control system for divertor configuration on QUEST, 27th Symposium on Fusion Technology (SOFT 2012), 2012.09, [URL], A plasma control system in order to sustain divertor configurations is developed on QUEST (Q-shu university experiment with steady-state spherical tokamak). Magnetic fluxes are numerically integrated by 100 kHz frequency with usage of FPGA (Field-Programmable Gate Array) modules, and transferred to a main calculation loop with 4 kHz. With these signals, plasma shapes are identified in real time with 2 kHz frequency under the assumption that the plasma current can be represented as one filament current. This calculation is done in another calculation loop in parallel by taking advantage of a multi-core processor of the plasma control system. The inside and outside plasma edge position controls are tested using PID (proportional–integral–derivative) control loops for target positions. Whereas the outside edge position can not be controlled by outer PF coil current, the inside edge position can be controlled by inner PF coil current.. |
| 31. | Makoto Hasegawa, Kazuo Nakamura, KAZUTOSHI TOKUNAGA, hideki zushi, kazuaki hanada, Akihide Fujisawa, Hiroshi Idei, Shoji Kawasaki, Hisatoshi Nakashima, Aki Higashijima, Development of Control System for Divertor Configuration on QUEST, 16th International Workshop on Spherical Torus (ISTW2011), 2011.09, [URL], In a similar way to other spherical tokamaks, the achievement of steady state operation with divertor configuration is one of important issues for the QUEST project. The control system for this has been developed in the QUEST. The identification of plasma position and its configuration is required for the control. One of the methods adopted in this control system is to adjust plasma shape parameters such as elongation and triangularity directly so that the calculated magnetic signals become the same values as measured ones. Although this method cannot be adopted if the plasma shape is complicated, one can expect that the time to calculate become short because there is no need to calculate values such as flux values at inside area of vacuum vessel but just installed positions of magnetic sensors. This calculation method has been installed into the control system of the QUEST which is composed of 4 CPU cores and Real Time-OS and operates main control loop with 4 kHz period. And, this calculation with 22 flux loop signals is finished within 1msec by using parallel processing technology. The horizontal and vertical plasma positions are controlled by active coils called HCUL coils and PF26 coils, respectively with simple PID control method. The current of PF26 coils changes not only vertical magnetic field but n-index. Furthermore, the n-index also varies gradually in the process that plasma configuration changes from limiter configuration to divertor configuration. This change affects vertical control, and the appropriate PID gain values differ by each magnetic configuration. For this, the mechanism to regulate each gain values automatically according to the magnetic configuration will be also installed into the control system. . |
| 32. | 長谷川 真, QUEST実験におけるSNET利用の現状紹介, 平成22年度NIFS共同研究 SNET／核融合バーチャルラボラトリ 合同研究会, 2011.02, [URL]. |
| 33. | 長谷川 真, QUEST計画における共同研究環境の構築, NIFS共同研究「SNETを用いた共同研究の進展」「核融合実験に関するバーチャル・ラボラトリー研究会」合同研究会, 2010.02. |
| 34. | 長谷川 真, 図子 秀樹, 花田 和明, 中村 一男, 藤澤 彰英, 坂本 瑞樹, 出射 浩, 東園 雄太, 川﨑 昌二, 中島 寿年, 東島 亜紀, プラズマ立上げと定常運転に向けた統合的な最適制御手法の確立, 九州大学総理工セミナー, 2009.12. |
| 35. | 長谷川 真, 中西 秀哉, 長山 好夫, 山本 孝志, 江本 雅彦, 東島 亜紀, 中村 一男, QUESTグループ, QUEST実験におけるSINET活用事例の紹介 , 学術認証フェデレーション及びSINETサービス説明会, 2009.12. |
| 36. | 長谷川真, QUEST実験におけるSNETの利用, NIFS共同研究「SNETを用いた共同研究の進展」「核融合実験に関するバーチャル・ラボラトリー研究会」, 2009.02. |
| 37. | 長谷川真, QＵESTの制御, 電気学会ST調査専門委員会, 2008.09. |
| 38. | 長谷川真, QUESTデータの取り扱いについて-QUEST実験データ閲覧システムの現状について-, 第2回QUEST研究会, 2008.07. |
| 39. | （核融合研）中西秀哉、小嶋 護、大砂真樹、今津節夫、野々村美貴、長山好夫、川端一男 （九大応力研）長谷川真、東島亜紀、中村一男 , 「核融合バーチャルラボラトリ」に向けた遠隔実験データ収集システムの整備拡充, 第7 回核融合エネルギー連合講演会, 2008.06. |
| 40. | 長谷川真、中村一男、東島亜紀, QUEST制御システムの開発, バーチャルラボラトリ研究会 核融合データ処理研究会, 2008.02. |
| 41. | 長谷川真、中西秀哉、中村一男、東島亜紀, LHDおよび九州大学プラズマ境界力学装置での遠隔実験・シミュレーション, 平成19年度第1回 SNETタスク会合「SNETを用いた共同研究の進展」, 2008.02. |
| 42. | M. Hasegawa, K. Nakamura, A. Higashijima, S. Kawasaki, H. Nakashima, K. N. Sato, H. Zushi, K. Hanada, M. Sakamoto, H. Idei, High Accessible Experimental Information on CPD Experiment, Sixth IAEA Technical Meeting on Control, Data Acquisition, and Remote Participation for Fusion Research, 2007.06. |
| 43. | 長谷川 真、坂本 瑞樹、出射 浩、中村 一男、花田 和明、図子 秀樹、佐藤 浩之助、＊高瀬 雄一、朝倉 伸幸、清水 勝宏, SOLDORを用いたQUESTダイバータ設計, プラズマ・核融合学会, 2006.11. |
| 44. | 長谷川真、坂本瑞樹、清水勝宏, QUESTにおけるダイバータシミュレーション, トライアム研究会, 2006.08. |
| 45. | 長谷川真、東島亜紀、中村一男, 全日本ST計画での計測データ処理・遠隔実験環境, NIFS共同研究「核融合実験のデータ処理に関する次世代システム技術の検討」研究会, 2006.02. |
| 46. | 長谷川真、東島亜紀、中村一男, TRIAMデータ処理系でのJavaScope利用の取組み, 次世代実験のための核融合データ処理システム技術検討作業会, 2004.05. |
| 47. | 長谷川真、中島寿年、川崎昌二、彌政敦洋、上瀧恵里子、坂本瑞樹、図子秀樹、中村一男、花田和明、伊藤智之, TRIAM-1Mにおける170GHz電子サイクロトロン波によるプラズマ生成, 日本物理学会２００２年秋季大会, 2002.09. |
| 48. | 長谷川真、トライアムグループ, TRIAM-1Mにおけるプラズマ電流立ち上げ実験, 第１５回TRIAM研究会, 2002.03. |
| 49. | 長谷川真、彌政敦洋、中島寿年、川崎昌二、上瀧恵里子、坂本瑞樹、図子秀樹、中村一男、花田和明、伊藤智之, TRIAM-1MのECH実験, プラズマ・核融合学会 九州・沖縄・山口支部第５回研究発表講演会, 2002.02. |
| 50. | 長谷川真、彌政敦洋、中島寿年、川崎昌二、上瀧恵里子、坂本瑞樹、図子秀樹、中村一男、花田和明, TRIAM-1Mにおける170GHz ECHシステムとプラズマ電流の立ち上げ実験, プラズマ・核融合学会 第１８回年会, 2001.11. |
| 51. | M. Hasegawa, TRIAM Group, Current Startup with an ECH System on TRIAM-1M, 43rd Annual Meeting of the Division of Plasma Physics, 2001.10. |
| 52. | 長谷川真、彌政敦洋、上瀧恵里子、坂本瑞樹、図子秀樹、中村一男、花田和明、伊藤智之, TRIAM-1MにおけるOHコイルを用いないプラズマ電流立ち上げ・維持実験, 日本物理学会２００１年秋季大会, 2001.09. |
| 53. | 長谷川真、TRIAM Group, ECH Experiments on TRIAM-1M, US-JP WS on Plasma Control and Long Sustainment using RF waves, 2001.02. |
| 54. | 長谷川真、中島寿年、川崎昌二、上瀧恵里子、花田和明、坂本瑞樹、図子秀樹、中村一男、伊藤智之, TRIAM-1Mの高効率電流駆動実験, プラズマ・核融合学会 九州・沖縄・山口支部第４回研究発表講演会, 2000.12. |
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