Investigation of merging/reconnection heating during solenoid-free startup of plasmas in the MAST Spherical Tokamak
Investigation of merging/reconnection heating during solenoid-free startup of plasmas in the MAST Spherical Tokamak
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DOI：
10.1088/1741-4326/aa6608
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发表时间：
2017-04
期刊：
影响因子：
3.3
通讯作者：
H. Tanabe;T. Yamada;Takenori G Watanabe;K. Gi;M. Inomoto;R. Imazawa;M. Gryaznevich;R. Scannell;N. Conway;C. Michael;B. Crowley;I. Fitzgerald;A. Meakins;N. Hawkes;K. McClements;J. Harrison;T. O’Gorman;C. Cheng;Y. Ono
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文献类型：
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作者：
H. Tanabe;T. Yamada;Takenori G Watanabe;K. Gi;M. Inomoto;R. Imazawa;M. Gryaznevich;R. Scannell;N. Conway;C. Michael;B. Crowley;I. Fitzgerald;A. Meakins;N. Hawkes;K. McClements;J. Harrison;T. O’Gorman;C. Cheng;Y. Ono
本文介绍了最近在巨磁球形托卡马克（MAST）中无中心螺线管（CS）等离子体启动过程中的合并/重联加热的研究结果。在这个过程中，离子在流出射流的下游区域被全局加热，并且由两个内部P3线圈和围绕这些线圈形成的两个等离子体环的磁场在X点周围局部产生电子，最终温度与重连场能量成比例。由于重新连接的通量的厚层，存在对下游热能的有效限制。该特征结构持续的时间长于离子-电子能量弛豫时间，并且离子和电子之间的能量交换有助于下游区域中的体电子加热。X点附近的峰值电子温度随环向场的增加而增加，但下游的电子和离子温度不随环向场的增加而改变。
We present results of recent studies of merging/reconnection heating during central solenoid (CS)-free plasma startup in the Mega Amp Spherical Tokamak (MAST). During this process, ions are heated globally in the downstream region of an outflow jet, and electrons locally around the X-point produced by the magnetic field of two internal P3 coils and of two plasma rings formed around these coils, the final temperature being proportional to the reconnecting field energy. There is an effective confinement of the downstream thermal energy, due to a thick layer of reconnected flux. The characteristic structure is sustained for longer than an ion–electron energy relaxation time, and the energy exchange between ions and electrons contributes to the bulk electron heating in the downstream region. The peak electron temperature around the X-point increases with toroidal field, but the downstream electron and ion temperatures do not change.