激光驱动的光阴极研究

INVESTIGATION OF PHOTOCATHODE DRIVEN BY A LASER

论述激光驱动的光阴极实验研究。包括直流高压真空试验系统，测试装置和实验结果及其分析讨论。ＬａＢ６、纯金属铜（Ｃｕ）和钐（Ｓｍ）以及半导体碲化铯（Ｃｓ２Ｔｅ）三类有代表性光阴极的量子效率分别是６×１０－４、３．８×１０－４、１１．６×１０－４和（２～６）×１０－２。利用ＫｒＦ激光，１８ｋＶ极间电压下饱和电流密度分别为７０Ａ／ｃｍ２、５０Ａ／ｃｍ２、１０２Ａ／ｃｍ２和５７Ａ／ｃｍ２。用多孔板法测得的归一化发射度约１０πｍｍ·ｍｒａｄ。

The experimental studies of photocathode driven by a laser are reported in this paper.The experimental systems including the D Cvoltage vacuum chamber and measurement apparatus are given.Also we will present the experimental results and discussions of LaB 6 ,pure metals(Cu,Sm)and Cs 2 Te semiconductor photocathode.The quantum efficiencies of photocathodes are6×10 -4 ,3.8×10 -4 ,11.6×10 -4 and(2～6)×10 -2 ,respectively,the corresponding photocurrent densities of 70A/cm 2 ,50A/cm 2 ,102A/cm 2 and57A/cm 2 are obtained. Using the pepper pot method,the normalized beam emittances for these materials are about 10πmm·mrad and the corresponding normalized brightnesses are about10 10 A/m 2·rad 2.