高能量大束流氩离子枪的研发  

Development of high energy and high flux argon ion gun

作　　者：朱美强 石晓倩 唐瓦 邓伟杰[2] 郭方准[1] ZHU Meiqiang;SHI Xiaoqian;TANG Wa;DENG Weijie;GUO Fangzhun(Dalian Jiaotong University,Dalian 116028,China;Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China)

机构地区：[1]大连交通大学,大连116028 [2]中国科学院长春光学精密机械与物理研究所,长春130033

出　　处：《核技术》2021年第9期39-44,共6页Nuclear Techniques

基　　金：国家自然科学基金(No.11803037)资助。

摘　　要：为了实现对大口径碳化硅非球面反射镜的表面改性层硅的高精度快速抛光,设计制作了高能量大束流氩离子枪。通过热灯丝和阳极栅网的组合实现氩原子的离子化,通过调节氩离子所处区域的电位来确定离子的能量,通过静电聚焦透镜来实现氩离子的聚焦。调节灯丝和阳极栅网之间的电压达到离子化率的最大化,调节静电聚焦透镜的尺寸和相对位置实现氩离子的高透过率。氩离子枪的材料选择既需满足超高真空使用又要避免产生真空放电。通过理论计算和模拟氩离子束流的轨迹,确定了氩离子枪各主要组件的参数。测试结果表明:氩离子的加速电压可达20 kV,在工作距离为30 mm和氩气分压为1.2×10^(−2) Pa的情况下,可产生50μA的氩离子束流,束斑的直径在19~24 mm之间连续可调。该氩离子枪体积小,可以安装在真空多维位移台上进行大范围的运动,实现对大口径光学元件的高真空表面抛光。[Background]Large size aspherical mirrors have been widely used in space communication systems because of their high angular resolution and energy harvesting ability.[Purpose]This study aims to develop a high energy and high flux argon(Ar)ion gun for the rapid polishing of modified silicon layer on the surface of large size SiC aspherical mirror.[Methods]First of all,Ar ionization was realized by filament and anode grid.Ar+energy was determined by anode voltage whilst the extractor and electrostatic lenses were employed to achieve Ar+emission and focusing.The high transmittance of argon ions was realized by adjusting the voltage between the filament and the anode grid to maximize the ionization rate,and adjusting the size and relative position of the electrostatic focusing lens.The materials in the Ar ion gun were selected not only suitable for ultra-high vacuum,but also preventing from vacuum discharge.Then,the parameters of the main components of argon ion gun were determined by theoretical calculation and simulation of the trajectory of argon ion beam.Finally,preliminary experimental tests were carried out to verify its performance.[Results]The test results show that the Ar+energy and beam flux can reach 20 keV and 50μA,respectively,at 30 mm working distance and Ar partial pressure of 1.2×10^(−2) Pa.The beam size can be continuously adjusted from 19 mm to 24 mm.[Conclusions]This developed argon ion gun with small size,high energy and high flux,can be installed on a vacuum multi-dimensional displacement table for a wide range of movement to achieve high vacuum surface polishing of large aperture optical elements.

关 键 词：氩离子枪 光学镜面抛光 表面科学 静电透镜 

分 类 号：TL99[核科学技术—核技术及应用]