Electron-impact excitation and ionization of W3+ for the determination of tungsten influx in a fusion plasma
Electron-impact excitation and ionization of W3+ for the determination of tungsten influx in a fusion plasma
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W3 的电子碰撞激发和电离用于测定聚变等离子体中的钨流入量
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
D. C. Griffin
中科院分区：
文献类型：
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作者：
C. Ballance;S. Loch;M. Pindzola;D. C. Griffin
在法国Cadarache建造的ITER聚变反应堆中，钨将被用作等离子体表面材料；因此，需要精确的钨离子的电子碰撞激发和电离数据。我们报告了W3+电离和激发的广泛计算结果，旨在为确定几个现有托卡马克反应堆中钨的杂质流入诊断提供所需的原子数据。本研究的电子冲击激发率系数采用相对论r矩阵法确定。利用扭曲波近似确定了直接电子冲击电离的贡献，并通过带有伪态计算的r矩阵验证了其准确性。激发自离化对总电离的贡献也由相对论性r矩阵方法得到。这些结果然后被用来计算每发射光子的电离值，或SXB比率，为四个精心选择的光谱线；这些数据将用于确定钨表面的杂质流入量。对于托卡马克反应堆边缘区域的重要密度范围，发现这些SXB比几乎与电子密度无关，但随着电子温度的变化而显著变化。
Tungsten will be employed as a plasma facing material in the ITER fusion reactor under construction in Cadarache, France; therefore, there is a significant need for accurate electron-impact excitation and ionization data for the ions of tungsten. We report on the results of extensive calculations of ionization and excitation for W3+ that are intended to provide the atomic data needed for the determination of impurity influx diagnostics of tungsten in several existing tokamak reactors. The electron-impact excitation rate coefficients for this study were determined using the relativistic R-matrix method. The contribution to direct electron-impact ionization was determined using the distorted-wave approximation, the accuracy of which was verified by an R-matrix with pseudo states calculation. Contributions to total ionization from excitation autoionization were also generated from the relativistic R-matrix method. These results were then employed to calculate values of ionization per emitted photon, or SXB ratios, for four carefully selected spectral lines; these data will allow the determination of impurity influx from tungsten facing surfaces. For the range of densities of importance in the edge region of a tokamak reactor, these SXB ratios are found to be nearly independent of electron density but vary significantly with electron temperature.