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

氢中性传输代码，包括 112 个振动激发和 H 辐射捕获，用于评估聚变边缘等离子体中的分子辅助复合

• 批准号: 15540470
• 负责人: SAWADA Keiji
• 金额: $ 2.05万
• 依托单位: SHINSHU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15540470/
• 关键词: hydrogen; molecule; molecular assisted recombination; MAR; collisional-radiative model; neutral transport code; vibrational excitation; radiation trapping

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.

在熔合边等离子体中，分子过程在粒子、动量和能量平衡中起着重要的作用。分离转向等离子体中的分子辅助复合（MAR）就是其中之一。通过建立氢原子和氢分子的碰撞辐射模型，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，其中不同振动态的分子被作为独立的物种追踪.在中性输运程序中，本文用新发展的迭代方法计算了受激态氢原子受辐射俘获的莱曼系列布居过程，代码应用于我们的RF等离子体和LHD等离子体。计算得到的射频等离子体中主量子数为3，4，5的氢原子布居数与光谱法测得的实验值吻合较好。计算的Ha在LHD等离子体中的谱线轮廓与实验谱线轮廓进行了比较。计算结果表明，激发态原子的主要产生过程是基态原子的电子碰撞激发，激发过程为H_2（v）+ e^->H_2^++2e; H_2^+ +e → H + H^+ + e和H_2（v）→ H + H^* → H + H。

项目成果

Iterative numerical method for inclusion of radiation trapping into collisional-radiative model

将辐射捕获纳入碰撞辐射模型的迭代数值方法

• 发表时间: 2006
• 期刊: J.Plasma Physics 72
• 作者: K.Sawada