Hydrogen neutral transport code which includes 112 vibrational excitation and H radiation trapping for evaluation of molecular assisted recombination in fusion edge plasmas

在聚变边缘等离子体中，分子过程在粒子、动量和能量平衡中起着重要的作用。分离偏转等离子体中的分子辅助复合(MAR)就是其中之一。通过建立原子氢和分子氢的碰撞-辐射模型，估算了分子过程的有效反应速率系数。我们发现MAR的速率系数强烈地依赖于分子氢的初始振动能级。我们构造了一个中性输运程序，将处于不同振动状态的分子作为独立物种追踪。在中性输运程序中，利用新开发的迭代方法考虑了通过Lyman系列辐射俘获激发的氢原子的布居过程。中性输运程序被应用于我们的射频等离子体和LHD等离子体。计算的主量子数为3、4、5的氢原子在射频等离子体中的布居数与用光谱方法测得的实验值有很好的重现性。计算了Ha在LHD等离子体中的谱线分布，并与实验谱线分布进行了比较。计算表明，激发态原子的主要产生过程是由H_2(V)+e^-&gt；H_2^++2e；H_2^++e→H+H^++e和H_2(V)→H+H^*→H+H产生的基态原子的电子碰撞激发。

In fusion edge plasmas, molecular processes play important role in particle, momentum and energy balances. The molecular assisted recombination (MAR) in detached diverter plasmas is one of them. We have estimated the effective reaction rate coefficient of the molecular processes by constructing collisional-radiative models of atomic hydrogen and molecular hydrogen. We have found the rate coefficient of the MAR depends strongly on the initial vibrational levels of molecular hydrogen.We have constructed a neutral transport code in which molecules in different vibrational states are traced as independent species.In the neutral transport code, the populating process of excited hydrogen atom by the radiation trapping of Lyman series has been included using newly developed iteration method in this study.The neutral transport code was applied to our RF plasmas and LHD plasmas. Calculated population of atomic hydrogen with principal quantum number 3, 4, 5 in the RF plasmas has well reproduced experimental values which were determined by spectroscopic method. Calculated Line profile of Ha in LHD plasmas was compared with experimental line profile. The calculation indicates the dominant process of production of the excited atoms is the electron impact excitation of the ground state atom which are produced by processes of H_2(v) + e^->H_2^+ + 2e; H_2^+ +e → H + H^+ + e and H_2(v)→ H + H^* → H + H.