太阳同步轨道真空紫外光电倍增管的高能粒子屏蔽方法研究

摘要

空间辐射环境是导致光电倍增管性能衰变甚至失效的主要原因，由于空间辐射环境的复杂性以及飞行器在空间活动的轨道、设计寿命和光电倍增管的类型不同，光电倍增管需要的抗辐射屏蔽要求不同．以太阳同步轨道高能粒子辐射环境为例，对真空紫外光电倍增管进行了辐射屏蔽的Monte-Carlo计算，在此基础上提出了运行于该轨道上的真空紫外光电倍增管的高能粒子屏蔽优化组合．模拟计算表明，采用Al-w-Al三层结构的屏蔽组合形式，其中A1层厚2mm，WW0．5mm，可将辐射剂量从原本的9．98×10^6rad（Si）降低到8．41×10^2rad（Si），能较好地满足实际使用要求．%The radiation environment of space accounts much for ultraviolet Photomultiplier Tube （PMT） performance degradation and even invalidation. The ultraviolet PMT＇s anti-radiation shielding methods depend on the environment of space radiation, spacecraft＇s orbital altitudes and their life expectancy as well as the type of ultraviolet PMT. Energetic particles environment of the sun syn- chronous orbit and Monte-Carlo simulation calculation are used in simulating PMT model＇s shielding effects. The calculation results supported an optimization design of shielding compositions for UV PMT on Sun-synchronous orbit. The simulations have determined an optimized shield constitutedby an Aluminum-Thngsten-Aluminum tri-layer. And each thickness is 2mm, 0.5mm, 2 mm. In a Sun-synchronous environment, the dose received by PMT will be decreased from 9.98 x 106 tad to 8.41 x 102 rad, and this optimized multilayer structure could meet our performance requirements. Key words Sun synchronous orbit, Ultraviolet, Photomultiplier, Energetic particles,