聚变等离子体鞘层能量传输系数分析

Analysis of sheath heat transmission coefficients for fusion plasma

对于磁约束聚变装置来说,可以用离子和电子的鞘层能量传输系数来预测和计算到达面向等离子体部件(PFC)的等离子体能量通量。文章推导并详细分析了悬浮态和非悬浮态的等离子体鞘层区域能量传输系数关系式。结果表明此系数随着边界等离子体的参数的变化而变化。并且当探针处于负偏压态时,探针面处的能量传输系数随着负偏压的增大而近似线性的增大。同时,也对发生在鞘层区域的能量转移过程进行了仔细分析,表明鞘层对于穿越的电子和离子分别相当于能量的冷却和加热装置。

For magnetic confinement fusion devices,the surface plasma heat flux arriving at PFC（plasma facing components） can be predicted and calculated by ion/electron sheath heat transmission coefficients.The simple relationships of the sheath heat transmission coefficients were derived and discussed for both floating and non-floating plasma sheath regions.The results indicated that the coefficients change with boundary plasma parameters,and when the probe is in negative bias state,the plasma sheath energy transfer coefficient increases almost linearly with the decreasing negative bias voltage.Moreover,the energy transfer process occuring within the sheath region was studied meticulously,and the result revealed that the sheath acts as a‘fridge’for high-energy electrons but an‘oven’for ions.