Development and characterization of the latest X-ray SOI pixel sensor for a future astronomical mission

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Vol. 731; pp. 74 - 78
• Main Authors: Nakashima, Shinya, Gando Ryu, Syukyo, Tanaka, Takaaki, Go Tsuru, Takeshi, Takeda, Ayaki, Arai, Yasuo, Imamura, Toshifumi, Ohmoto, Takafumi, Iwata, Atsushi
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2013
• Subjects: Accelerators; Active pixel sensor; Astronomy; Charge; Collection; Imaging spectrometer; Pixels; SOI; Space missions; Spectroscopy; X-ray astronomy; X-rays; X-ray astronomy; Active pixel sensor; SOI; Imaging spectrometer
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/j.nima.2013.04.063

We have been developing active pixel sensors based on silicon-on-insulator technology for future X-ray astronomy missions. Recently we fabricated the new prototype named “XRPIX2”, and investigated its spectroscopic performance. For comparison and evaluation of different chip designs, XRPIX2 consists of 3 pixel types: Small Pixel, Large Pixel 1, and Large Pixel 2. In Small Pixel, we found that the gains of the 68% pixels are within 1.4% of the mean value, and the energy resolution is 656eV (FWHM) for 8keV X-rays, which is the best spectroscopic performance in our development. The pixel pitch of Large Pixel 1 and Large Pixel 2 is twice as large as that of Small Pixel. Charge sharing events are successfully reduced for Large Pixel 1. Moreover Large Pixel 2 has multiple nodes for charge collection in a pixel. We confirmed that the multi-nodes structure is effective to increase charge collection efficiency. •We performed the evaluation of the newly fabricated SOI sensor for X-ray astronomy.•The pixel-to-pixel gain variation is small in the 64 ×144 pixel format.•The energy resolution is improved by the optimization of the pixel design.•The multi charge collection nodes improved the charge collection efficiency.