We have been developing P-channel Charge-Coupled Devices (CCDs) for the upcoming X-ray Astronomy Satellite XRISM, planned to be launched in 2021. While the basic design of the CCD camera (Soft X-ray Imager: SXI) is almost the same as that of the lost Hitomi (ASTRO-H) observatory, we are planning to reduce the phenomenon of “light leakages” that is one of the largest problems recognized in Hitomi data. We adopted a double-layer optical blocking layer on the XRISM CCDs and also added an extra aluminum layer on the backside of them. We develop a newly designed test sample CCD and irradiate it with optical light to evaluate the optical blocking performance. As a result, light leakages are effectively reduced compared with that of the Hitomi CCDs. We thus conclude that the issue is solved by the new design and that the XRISM CCDs satisfy the mission requirement for the SXI.

我们正在为计划于2021年发射的即将到来的X射线天文学卫星XRISM开发P沟道电荷耦合器件（CCD）。CCD相机（软X射线成像仪：SXI）的基本设计几乎是与丢失的瞳孔（ASTRO-H）天文台一样，我们正计划减少“漏光”现象，这是瞳孔数据中公认的最大问题之一。我们在XRISM CCD上采用了双层光学阻挡层，并在其背面增加了一层额外的铝层。我们开发了新设计的测试样品CCD，并用光照射以评估其光学阻挡性能。结果，与瞳孔CCD相比，有效地减少了漏光。