磁场辅助的小型化潘宁离子源点时燃放电特性研究

Study on the Characteristics of Ignition Discharge of A Small Penning Ion Source by Increasing Magnetic Field

潘宁离子源在小型化过程中会遇到点燃电压升高及阴极与阳极间绝缘材料击穿和不稳定放电等问题。为促使潘宁离子源内部结构小型化,文中在恒定电场下,通过增加磁场的方式实现潘宁离子源稳定放电,达到降电压放电,并延长了绝缘材料使用寿命,实现了稳定放电。此外,采用COMSOL Multiphysics软件对改进后的离子源内部电场、磁场的分布进行仿真,模拟分析电子在不同区域的运动和电离情况,据此建立了基于恒定电场增加磁场的点燃物理模型。该模型与实际的点燃实验进行对比的结果表明,改进后的小型潘宁离子源在电压恒定为0.8 kV时,仅将磁场增强至156.29 mT即可实现小型潘宁离子源稳定放电。

During the miniaturization of Penning ion source,there are some problems such as the increase of ignition voltage,breakdown of insulating material between cathode and anode and unstable discharge.In order to promote the miniaturization of the internal structure of the Penning ion source,the stable discharge of the Penning ion source is achieved by increasing the magnetic field under the constant electric field,the voltage drop discharge is achieved,the service life of the insulating material is extended,and the stable discharge is achieved.In addition,COMSOL Multiphysics software is used to simulate the distribution of electric field and magnetic field inside the improved ion source,and to simulate and analyze the motion and ionization of electrons in different regions.Based on this,a physical model of ignition based on constant electric field and magnetic field is established.The results of comparison between the model and the actual ignition experiment show that the improved small Penning ion source can realize stable discharge only by increasing the magnetic field to 156.29 mT under the condition of constant voltage of 0.8kV.