大面积单激励器射频离子源等离子体均匀性分析

Plasma Uniformity Study of Large-area Radio Frequency Negative Ion Source with One Driver

为了提高等离子体分布均匀度,基于有限元分析法与实验相结合的方法,从射频离子源驱动器尺寸和引出区尺寸2个方面对单驱动射频离子源放电室进行设计。模拟研究结果表明,电子均匀度的增长幅度随驱动器尺寸的大小变化比较缓慢。根据不同驱动器尺寸电子密度分布研究结果,在引出区尺寸为320 mm时,电子均匀度能够满足90%的要求。根据实验研究结果表明,在引出区尺寸为320 mm时电子分布均匀且均匀度>90%,并与模拟结果相吻合。因此,为使得等离子体分布均匀度能够达到要求,离子源放电室底部引出面附近引出区尺寸应该设计为320 mm。

The uniformity of distribution of plasma,which is connected with the plasma generation,is an important reference index in the process of ion source design.There are two factors that research activity has been studied,which are size of driver and length of extracted area.And the method based on the combination of finite element and experiment,has been adopted to improve the uniformity of distribution of plasma in the process of analysis.The simulation results show that the electronic uniformity increases slowly with the size of driver.However,it is worth noting that the data of electronic density of different driver sizes show that uniformity of electron can meet the requirements of 90%when the size of the extraction area is 320 mm.The experimental results show that the electron distribution is uniform and the uniformity is greater than 90%when the size of the extraction region is 320 mm,which is in agreement with the simulation results.In order to meet the requirement of plasma uniformity,the extraction region which is situated at the bottom of expansion chamber is necessary to be 320 mm.