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2019/3/19(二)14:10綜合大樓1樓48111B教室演講 : Prof. Masayoshi Nagata(Graduate School of Engineering, University of Hyogo, Japan)

張貼者:2019年3月18日 上午12:12Dabby Lu   [ Ann-Chen Jang 已於 2019年3月18日 上午12:12 更新 ]
講題: Coaxial Helicity Injection and Compact Torus Injection Experiments by Magnetized Coaxial Plasma Gun
摘要: The magnetized coaxial plasma gun (MCPG) can produce successfully the compact torus (CT) of a spheromak configuration and spherical torus (ST) plasmas. Thus, the MCPG is well utilized in many fusion plasmas and basic plasma physics experiments. 
Coaxial Helicity Injection (CHI) and Compact Torus Injection (CTI) are attractive fusion applications of the MCPG technology. The CHI is one of non-inductive current drive (plasma start-up and sustainment) methods in spheromak and spherical torus (ST) plasmas. The CHI current drive has been successfully demonstrated in SSPX (LLNL), HIST (U. Hyogo), HIT-II (U. Washington), NSTX (PPPL) and SPECTOR (General Fusion) devices. In the HIST experiments, we have investigated MHD relaxation, dynamo and magnetic reconnection which are related to mechanism of current drive and formation of closed flux surfaces. One of recent topics of CHI on STs is the study of the fast reconnection based on plasmoid instabilities. Intensive internal magnetic field measurements on HIST have recently verified the flux closure due to plasmoid-driven reconnection. 
The CT injection is used for the central fueling, density profile control, plasma rotation, disruption mitigation, ELM-like pulsed heat flux irradiation and so on. The advanced fueling technology should be developed for the fusion reactor. So far, the deep fueling by CT injection has been successfully demonstrated in JFT-2M (JAERI and U. Hyogo), QUEST (Kyusyu U. and U. Hyogo), TdeV (CFFTP, Canada) and STOR-M (U. Saskatchewan, Canada) tokamak devices. We have been conducting pioneering research in this area. The CT is a high density plasma (>1022 m-3) and is magnetically confined by internally self-generated magnetic fields. Thus the CT can be accelerated by the MCPG to a high velocity (> 300 km/s). The penetration mechanism of an injected CT plasmoid into the core plasma is associated with the magnetic reconnection physics.
In this seminar, we will introduce firstly the fundamental of CT/ST magnetic configurations and how to use the MCPG, and then talk about the recent topics of CHI and CTI experiments.
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Ann-Chen Jang,
2019年3月18日 上午12:12
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