研制了一套基于计算机控制的GaAs光电阴极智能激活系统,该系统可在计算机控制下严格按照标准工艺对GaAs光电阴极进行智能激活,并可在线测量阴极的光谱响应曲线。利用该系统分别进行了智能激活和人工激活实验,采集了激活过程中的光电流变化曲线,分析发现,和智能激活过程相比,由于人工激活过程出现了误操作,相邻光电流峰值间的差值下降很快,Cs、O交替的次数也较少。人工激活过程中Cs、O交替6次,光电流最大值为43μA,激活后GaAs光电阴极的积分灵敏度为796μA/lm。智能激活过程中Cs、O交替9次,光电流最大值为65μA,激活后GaAs光电阴极的积分灵敏度为1100μA/lm。
The computer-automated system has been successfully developed to intelligently activate the GaAs photocathode by the standardized activation technique and to evaluate in-situ the spectral response. The time evolutions of the photocurrent during both the manual activation and auto-activation with the system were compared. The comparisons show that the auto-activation outperforms the manual activation. In the manual-activation,the photocurrent increases more slowly,the peak photocurrent decreases faster,and the (Cs,O) alternation number is fewer as compared with the auto-activation, possibly because of some mis-operation. For instance, in manual activation of the GaAs photocathede, we observed the (Cs, O) alternation number of 6, a peak photocurrent of 43μA and an integrated sensitivity of 796μA/lm; whereas in auto-activation, the (Cs, O) ahemation number of 9, a peak photocurrent of 65μA and an integrated sensitivity of 1100μA/lm.