Soft x-ray transmission of contamination blocking filter for SXI onboard ASTRO-H
Soft x-ray transmission of contamination blocking filter for SXI onboard ASTRO-H
复制标题
用于 ASTRO-H 上 SXI 的污染物阻挡过滤器的软 X 射线透射
DOI：
10.1117/12.2056473
复制
发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Y.
中科院分区：
文献类型：
--
作者：
T. Kohmura.;K. Kaneko.;H. Tsunemi.;K. Hayashida.;R. Nagino.;S. Inoue.;D. Uchida.;S. Katada.;T. Dotani.;M. Ozaki.;H. Tomida.;M. Kimura.;T.G. Tsuru.;S. Ikeda.;K. Yabe.;K. Miyakawa.;M. Andoh.;S. Kuwano.;Y. Sato.;K. Tamasawa.;S. Tanno.;Y.
卫星上运行的X射线CCD被卫星使用的有机材料排放的气体污染。这种污染导致X射线探测器的探测灵敏度显著降低。为了防止这种污染对ASTRO-H上的软X射线成像仪(SXI)的背照式电荷耦合器件(BI-CCD)造成污染，我们研制了一种由~30 nm厚的铝和~200 nm厚的聚酰亚胺组成的污染阻挡滤光片。CBF被放置在CCD相机罩的顶部，为了利用BI-CCD的高探测效率，要求具有高的X射线透过率。我们于去年10月在春8号测量了CBF的三个飞行候选者的X射线透过率，得到了三个CBF在0.2到1.8keV的软X射线能量范围内的X射线透过率，该软X射线能量覆盖了C-K，N-K，O-K和Al-K周围的吸收边，包括X射线吸收精细结构(XAFS)。在这些测量中，我们发现有三个CBF在2keV以下具有很高的X射线透过率，例如在0.5keV左右有~70%的透过率，并确定Al和聚酰亚胺的厚度分别为220 nm和~50 nm。我们将计算包含这些结果的SXI的响应函数。
X-ray CCD operated onboard satellite are contaminated by outgas from organic material used in satellites. This contamination causes a significant reduction in the detection sensitivity of X-ray detectors. In order to prevent such contamination to the Back-Illuminated CCD (BI-CCD) of the Soft X-ray Imager (SXI) onboard ASTRO-H, we have developed a Contamination Blocking Filter (CBF), which consists of ~30nm thick Aluminum and ~200nm thick Polyimide. The CBF is be placed on the top of the CCD camera hood and is required to have a high X-ray transmission in order to take advantage of the high detection efficiency of BI-CCD. We measured the X-ray transmission of three flight candidates of the CBF last October at the SPring-8 and obtained the X-ray transmission of three CBFs in the soft X-ray energy from 0.2 to 1.8 keV which covers the absorption edges around C-K, N-K, O-K, and Al-K including X-ray absorption fine structure (XAFS). In these measurements, we found three CBFs have high X-ray transmission below 2ke V, e.g. ~70% at around 0.5 keV, and determined the thickness of Al and Polyimide to be 220 nm and ~50 nm, respectively. We will calculate the response function of SXI including these results.