Extension of the operating space of high-bN fully non-inductive scenarios on TCV using neutral beam injection
Extension of the operating space of high-bN fully non-inductive scenarios on TCV using neutral beam injection
复制标题
使用中性束注入扩展 TCV 上高 bN 全无感场景的操作空间
DOI：
10.1088/1741-4326/ab2bb6
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发表时间：
2019
期刊：
影响因子：
3.3
通讯作者：
他13名
中科院分区：
文献类型：
--
作者：
C. Piron;J. Garcia;M. Yoshida;他13名
高归一化β等离子体的完全无感维持是托卡马克反应堆稳态运行的一个关键挑战。为了评估此类场景面临的困难，使用新推出的 1 MW 中性束注入 (NBI) 系统对托卡马克配置变量 (TCV) 的稳态状态进行了探索。操作空间扩展到更接近 JT-60SA 和 ITER 中预期的等离子体，即具有显着的 NBI 和电子回旋共振加热和电流驱动 (ECRH/CD)、自举电流和快离子 (FI) 分数。在零时间平均环路电压 和 时，在较低的单零 L 模式 () 和 H 模式 () 等离子体中分别获得高达 1.4 和 1.7 的值。仅使用 NBI 无法实现完全无感操作，在存在 EC 波的情况下，NBI 的注入甚至会增加环路电压。解释性 ASTRA 和 NUBEAM 模型通过实验证明和证实了 NBI 对热和 FI 总等离子体压力的重要贡献，该模型进一步预测 FI 电荷交换反应是 NBH/CD 效率的主要损失通道。尽管环形旋转和 NBI 的 FI 分数显着增加（众所周知，NBI 可以减少湍流），但迄今为止探索的等离子体中的电子或离子通道中都没有形成内部传输势垒，预计可以最大化自举电流分数。还介绍了高全无感 H 模式等离子体场景开发的初步结果。
The fully non-inductive sustainment of high normalized beta plasmas () is a crucial challenge for the steady-state operation of a tokamak reactor. In order to assess the difficulties facing such scenarios, steady-state regimes have been explored on the tokamak à configuration variable (TCV) using the newly available 1 MW neutral beam injection (NBI) system. The operating space is extended towards plasmas that are closer to those expected in JT-60SA and ITER, ie with significant NBI and electron cyclotron resonance heating and current drive (ECRH/CD), bootstrap current and fast ion (FI) fraction. values up to 1.4 and 1.7 are obtained in lower single null L-mode () and H-mode () plasmas, respectively, at zero time averaged loop voltage and. Fully non-inductive operation is not achieved with NBI alone, whose injection can even increase the loop voltage in the presence of EC waves. A strong contribution to the total plasma pressure of thermal and FIs from NBI is experimentally evidenced and confirmed by interpretative ASTRA and NUBEAM modeling, which further predicts that FI charge-exchange reactions are the main loss channel for NBH/CD efficiency. Internal transport barriers, which are expected to maximize the bootstrap current fraction, are not formed in either the electron or the ion channel in the plasmas explored to date, despite a significant increase in the toroidal rotation and FI fraction with NBI, which are known to reduce turbulence. First results on scenario development of high-fully non-inductive H-mode plasmas are also presented.