Modeling of gas flow in the simulation of H− ion source
Modeling of gas flow in the simulation of H− ion source
复制标题
H− 离子源模拟中的气流建模
DOI：
10.1063/1.1146763
复制
发表时间：
1996
影响因子：
1.6
通讯作者：
A. Hatayama
中科院分区：
文献类型：
--
作者：
M. Ogasawara;Y. Okuda;M. Shirai;S. Mitsuhashi;A. Hatayama
对进入离子源的实际气体供应进行建模。填充压力与气体流速和H−提取系统的电导率有关。采用氢分子的速率方程，对负氢离子源进行了数值模拟。数值模拟结果表明，H数守恒关系和压强平衡方程不准确，特别是在较高的电子温度下。实际上，对于5eV的电子温度，损失的H2密度达到79%，并且压力变为5 mTorr的原始压力的5倍。即使对于3 mTorr的低压，对于5 eV的电子温度，损失分数也是67%。这种不准确性在离子源的高功率中是大的，甚至对于离子源的低压操作也是如此。
Actual gas supply into the ion source is modeled. Filling pressure is related to gas flow rate and conductance of the H− extraction system. The rate equation for the H2 molecule with gas inflow and outflow rates related with the filling pressure are employed in the numerical simulation of a negative hydrogen ion source. With the results of numerical simulation, the H number conservation relation and pressure balance equation are shown to be inaccurate especially for higher electron temperature. Actually for 5 eV of electron temperature, lost H2 density amounts to 79% and the pressure becomes 5 times the original pressure of 5 mTorr. Even for a low pressure of 3 mTorr, the lost fraction is 67% for 5 eV of the electron temperature. This inaccuracy is large in high power and even for low pressure operation of the ion source.