Density profile transition and high-energy electron transport in a magnetically expanding radio frequency plasma
Density profile transition and high-energy electron transport in a magnetically expanding radio frequency plasma
复制标题
DOI：
10.1063/5.0126901
复制
发表时间：
2023-01
影响因子：
2.2
通讯作者：
Kazuma Emoto;Kazunori Takahashi;Y. Takao
中科院分区：
文献类型：
--
作者：
Kazuma Emoto;Kazunori Takahashi;Y. Takao
使用单元内粒子和蒙特卡罗碰撞技术研究了磁膨胀射频 (RF) 等离子体中的密度分布转变和高能电子传输，其中等离子体源和扩散区域均得到自洽模拟。模拟结果表明，随着磁场强度的增加，密度分布从中心峰值变为双峰等离子体，而在之前的实验中观察到了双峰等离子体。然后，讨论了关于电离、电子温度和高能电子密度的密度分布转变。这表明电子被射频场加热并穿过磁场线径向向内传输。高能电子的移动距离可以通过电子中性弹性碰撞来解释。因此，密度的形成取决于电子被加热的位置以及高能电子通过弹性碰撞传输的距离，这意味着远离射频天线径向向内移动的高能电子的存在时间更长。
The density profile transition and high-energy electron transport in a magnetically expanding radio frequency (RF) plasma were investigated using particle-in-cell and Monte Carlo collision techniques, where both the plasma source and the diffusion region were simulated self-consistently. The simulation results show that the density profile changes from center-peaked to bimodal plasma with increasing magnetic field strength, where bimodal plasma was observed in previous experiments. Then, the density profile transition is discussed with respect to ionization, electron temperature, and high-energy electron density. This indicates that electrons were heated by the RF field and transported radially inward across magnetic field lines. The moving distance of high-energy electrons is explained by an electron-neutral elastic collision. Therefore, the density formation depends on where the electrons are heated and how far the high-energy electrons are transported by an elastic collision, implying the longer existing time of high-energy electrons that move radially inward away from the RF antenna.