质子辐照对极紫外波段滤光片透过率的影响

Effect of proton irradiation on transmittance of Al filter at EUV waveband

为了检验应用在极紫外波段空间太阳望远镜上Al滤光片在空间辐照环境下透过率的变化情况,用能量100keV,剂量为6×1011/mm2的质子束对其进行辐照,利用透射电子显微镜分析了质子辐照前后滤光片的微观结构。实验结果表明:由于质子辐照使滤光片受质子侵蚀后,Al原子被击出发生质量损失,表面形态发生了变化,造成滤光片变薄,从而导致透过率由辐照前的12.1%增大到15.0%,且滤光片的薄厚分布不均匀使透过率曲线出现了次级峰,造成其光学性能的退化。

Part of low-earth orbit＇s space radiation environment was simulated to investigate the influence on the transmittance change of the aluminum filter used on the space solar telescope in extreme-ultraviolet（EUV） waveband. The transmittance was measured before and after proton irradiation with energy of 100 keV and dose of 6×10^11/mm^2. And the microstructures of a luminum filter were investigated by transmission electron microscopy（TEM）. The experimental results show that the transmittance of filter increases from 12.1% to 15.0 % because of the thickness decrease of filter after proton irradiation, and the thickness of the filter beoames inhomogeneous, resulting in the optical performance degradation of the filter and sub-peak in the transmit tance curve. The reason is that aluminum atoms are stricken out and the filter surface configuration changes when the filter is corroded by proton irradiation.