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

本研究的目的是研制一种能够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)灯泡气体的性质，(2)气压，(3)火花高压，(4)火花电路，(5)电极结构等，特别是测试了Ar，Xe，H_2，N_2气体：其中Xe是高效发光的，尽管光输出的脉冲宽度很宽。另一方面，研究发现，在所研究的气体中，氮气的脉冲最窄。实验还发现，气体压力和/或火花电压越高，光产率越大。然而，光脉冲宽度与这两个参数几乎没有关系。至于火花电路，重要的是要以一种满足临界阻尼条件的方式进行调整。阴阳极间隙长度不同，分别为0.5、1.5和3.0 mm。发现点灯所需的最小火花电压随着间隙的加宽而增加，光脉冲随着间隙的加宽而变长。另一方面，与其他两种配置相比，0.5 mm间距的光产额效率略小。作为最后的测试，我们检查了具有2个ATM的灯的光输出的稳定性。具有1.5 mm另一阴极间隙的氮气：相对稳定性为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).