Optical blocking performance of CCDs developed for the X-ray Astronomy Satellite XRISM
Abstract
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.
- Publication:
-
Nuclear Instruments and Methods in Physics Research A
- Pub Date:
- October 2020
- DOI:
- arXiv:
- arXiv:2007.07608
- Bibcode:
- 2020NIMPA.97864374U
- Keywords:
-
- X-ray detectors;
- Charge-coupled device;
- XRISM;
- Astrophysics - Instrumentation and Methods for Astrophysics
- E-Print:
- 6 pages, 4 figures, accepted for publication in NIMA, proceedings of the 12th International "Hiroshima" Symposium on the Development and Application of Semiconductor Tracking Detector (HSTD12)