Development of a stable short-pulse-width flash lamp.

本研究工作的目的是研制一种可用于监测光电倍增管增益变化的稳定的短脉冲闪光灯。我们研究了（1）灯气体的性质，（2）气体压力，（3）火花高压，（4）火花电路，（5）电极结构等。特别是，我们测试了Ar、Ar、H2、N2气体：其中，发现Ar在产生光方面是有效的，尽管光输出的脉冲宽度很宽。另一方面，发现N2在所研究的气体中给出最窄的脉冲。还发现，随着气体压力和/或火花电压的升高，光产额更大。然而，光脉冲宽度对这两个参数的依赖性很小。至于火花电路，重要的是要以满足临界阻尼条件的方式进行调谐。阳极-阴极间隙长度不同;我们选择0.5、1.5和3.0 mm间隙。发现点燃灯所需的最小火花电压随着差距变宽而增加，并且光脉冲随着差距变宽而变长。另一方面，与其他两种配置相比，0.5mm间隙的光输出效率稍小。作为最后的测试，我们检查了2个大气压的灯的光输出的稳定性。N_2气体，另一阴极间隙为1.5mm：相对稳定度为4%（rms）。

The purpose of this research work is to develop a stable shortpulse flash lamp which can be used to monitor photomultiplier gain variations. We have studied(1)properties of lamp gas, (2)gas pressure, (3)spark high-voltage, (4)spark circuit, (5)electrode structure, etc. In particular, we tested Ar, Xe, H2, N2 gases : Of these, Xe was found to be efficient in producing light although the pulse width of light output was wide. On the other hand, N2 was found to give the narrowest pulse among the studied gases. It was also found that the light yield was larger as the gas pressure and/or the spark voltage was higher. The light pulse width, however, had little dependence on these two parameters. As for the spark circuit, it was important to tune in such a way that it fulfilled the critical damping condition. The anode-cathode gap length was varied ; we chose 0.5, 1.5 and 3.0 mm gap. The minimum spark voltage necessary to fire lamps was found to increase as the gap widened and the light pulse became longer as the gap widened. The light yield efficiency, on the other hand, was little smaller for 0.5mm gap compared with the other two configurations. As a final test, we checked the stability of light output for a lamp of 2 atm. N2 gas with 1.5mm anothercathode gap : the relative stability was found to be 4%(rms).