为了获得高亮度和高品质的电子束,在自由电子激光实验装置中采用光阴极注入器作为电子源,其驱动激光器系统采用主振功率放大结构,振荡器为二极管抽运连续锁模激光器,放大器为一级双程及两级单程二极管脉冲抽运放大,后接4倍频系统。经过工程研制及调试,获得的输出指标为:波长266nm,微脉冲能量4μJ,宏脉冲宽度2μs至6μs可调,微脉冲能量抖动优于3%。结果表明,采用Cs2Te阴极的光阴极注入器实验,该系统能够获得不低于40A的电子束流,达到了自由电子激光实验对电子源的束流要求。

In order to achieve high quality and high brightness electron beam,a photocathode injector is used as the electron source in the experimental setup of a free electron laser (FEL).The drive laser system is a master oscillator power amplifier configuration,consisting of a confinuous wave diode-pumped mode-locked oscillator,one double-pass and two single-pass regenerative diode-pumped pulse amplifiers and a four fold frequency conversion part.After adjustment,single micropulse energy of 4μJ with less than 3 percent of jitter at wavelength 266nm was obtained.These micropulses were contained within a macropulse envelope as long as 2μs to 6μs.In the experiments,adopting Cs2Te photocathode as the photoinjector, more than 40A electron beam was obtained,meeting the requirement of beam current for the FEL.