激光致等离子体中离子引出的空间分布特性研究

Distribution Characteristics of Ion Collection during Ion Extraction from Laser-Induced Plasma

对于原子法激光分离同位素(AVLIS),离子引出的特性研究具有十分重要的意义。采用YAG脉冲激光的四倍频输出与两平行平面极板间空气相互作用产生等离子体。极板间加几百伏电压,使离子从极板间的等离子体中引出。采用特殊设计的极板结构和实验装置,研究了电荷收集量在极板上的分布。通过对数据的分析,总结了离子引出过程中等离子体扩散效应,并发现离子引出的空间分布与极板间距有关,而与极板间电压基本无关。

Study on ion extraction characteristics is of great significance for Atomic Vapor Laser Isotope Separation （AVLIS）. Plasma was instantly produced after the interaction between the air and the YAG laser pulse quadruple output in the interspace of parallel-plate electrodes in the vacuum chamber. Ion was extracted from the plasma by a few hundreds of volts applied over the parallel-plate electrodes. With special electrodes configuration and experimental devices, further study was developed about ion collection distribution on the negative plate. Through the analysis of the signals under different conditions, diffusion effect of plasma was discussed. It is concluded that distribution of ion collection depends on the distance between electrodes and has little to do with the voltage over the electrodes.