The power threshold of H-mode access in mixed hydrogen–tritium and pure tritium plasmas at JET with ITER-like wall
The power threshold of H-mode access in mixed hydrogen–tritium and pure tritium plasmas at JET with ITER-like wall
复制标题
在具有类似 ITER 壁的 JET 中混合氢-氚和纯氚等离子体中 H 模式进入的功率阈值
DOI：
10.1088/1741-4326/ac6d6b
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发表时间：
2022
期刊：
影响因子：
3.3
通讯作者：
H. Weisen
中科院分区：
文献类型：
--
作者：
G. Birkenmeier;E. Solano;E. Lerche;D. Taylor;D. Gallart;M. Mantsinen;E. Delabie;I. Carvalho;P. Carvalho;E. Pawelec;J. Hillesheim;F. Parra Diaz;C. Silva;S. Aleiferis;J. Bernardo;A. Boboc;D. Douai;E. Litherland;R. Henriques;K. Kirov;C. Maggi;J. Mailloux;M. Maslov;F. Rimini;S. Silburn;P. Sirén;H. Weisen
进入高约束模式（H模式）的加热功率P LH与过去几十年中在许多聚变设施中的（质子）氢、氘和氚等离子体中发现的主要离子等离子体物质的同位素质量大致成反比。在首次专门的L-H跃迁实验中，在1.8T的磁场和1.7MA的等离子体电流下，系统地研究了纯氚和氢-氚混合物等离子体中的功率阈值P_LH，以评估这种标度在金属壁装置中是否仍然成立。测量的功率阈值，P LH，在欧姆加热的氚等离子体同意与预期的同位素缩放金属壁和最低的功率阈值被发现在欧姆相在低密度。由于较高的辐射水平，在纯氚或氢-氚混合物的离子回旋加热等离子体中测得的功率阈值显著高于预期的同位素质量标度。然而，当考虑到辐射功率时，离子回旋加速器加热的等离子体表现出与中性束加热的等离子体相似的功率阈值，并且接近缩放。在这项研究中的氚等离子体倾向于更高的电子加热分数，当加热与离子回旋波，相对较高的辐射分数相比，其他同位素可能阻碍访问持续的H-模式。
The heating power to access the high confinement mode (H-mode), P LH, scales approximately inversely with the isotope mass of the main ion plasma species as found in (protonic) hydrogen, deuterium and tritium plasmas in many fusion facilities over the last decades. In first dedicated L–H transition experiments at the Joint European Torus (JET) tokamak facility with the ITER-like wall (ILW), the power threshold, P LH, was studied systematically in plasmas of pure tritium and hydrogen–tritium mixtures at a magnetic field of 1.8 T and a plasma current of 1.7 MA in order to assess whether this scaling still holds in a metallic wall device. The measured power thresholds, P LH, in Ohmically heated tritium plasmas agree well with the expected isotope scaling for metallic walls and the lowest power threshold was found in Ohmic phases at low density. The measured power thresholds in ion cyclotron heated plasmas of pure tritium or hydrogen–tritium mixtures are significantly higher than the expected isotope mass scaling due to higher radiation levels. However, when the radiated power is taken into account, the ion cyclotron heated plasmas exhibit similar power thresholds as a neutral beam heated plasma, and are close to the scaling. The tritium plasmas in this study tended to higher electron heating fractions and, when heated with ion cyclotron waves, to relatively higher radiation fractions compared to other isotopes potentially impeding access to sustained H-modes.