猝发双脉冲直线感应加速器组元研究

在原单脉冲直线感应加速器（LIA）组元的基础上，利用电缆延时和电缆反射两种方式获得了间隔500～1 000 ns的猝发双脉冲输出。在感应加速腔上进行了双脉冲实验，获得了幅度大于200 kV、前沿小于35 ns、平顶大于60 ns的双脉冲加速电压波形。两种方式中第一个脉冲的前沿和幅度都达到了原单脉冲组元的水平，表明加速腔负载的变化对波形没有明显影响，但由于电缆对波形的损耗，第二个脉冲的幅度和前沿比第一个脉冲略差。可以利用水介质传输线来代替长电缆，减小传输线的长度及其对波形的损耗。两个脉冲间的幅度差异可以通过改变长电缆的阻抗来调节。实验表明，通过这两种猝发双脉冲的产生方式并结合加速腔磁芯的改进，可简单高效地完成原单脉冲LIA的双脉冲改造。

Current expansion of high-power diode laser bars

980 nm GaAs/AlGaAs separate confinement hetero-structure single quantum well laser bars were grown by metal organic chemical vapor deposition. The relationships between the etching depth and the bars’ parameters have been studied. When the bar is not etched deep to the active layer, the output power and the slope efficiency are in direct proportion to the etching depth, while the threshold current are in inverse proportion to the etching depth. When the bar is etched deeper than the active layer, the output power and the slope efficiency become lower and the threshold current become higher. The best etching depth is 1.993 mm in the experiment, which is less than the depth of the active layer.