Performance of a low noise front-end ASIC for Si/CdTe detectors in Compton gamma-ray telescope

• Published in: IEEE transactions on nuclear science Vol. 51; no. 3; pp. 842 - 847
• Main Authors: Tajima, H., Nakamoto, T., Tanaka, T., Uno, S., Mitani, T., Silva, Ed.Ce, Fukazawa, Y., Kamae, T., Madejski, G., Marlow, D., Nakazawa, K., Nomachi, M., Okada, Y., Takahashi, T.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.06.2004; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Angular resolution; Application specific integrated circuits; Cadmium tellurides; Decision support systems; Detectors; Energy resolution; Gamma ray detection; Gamma ray detectors; Integrated circuit noise; Low noise; Semiconductor device noise; Semiconductors; Silicon; Space technology; Telescopes
• ISSN: 0018-9499; 1558-1578
• DOI: 10.1109/TNS.2004.829394

Compton telescopes based on semiconductor technologies are being developed to explore the gamma-ray universe in an energy band 0.1-20 MeV, which is not well covered by the present or near-future gamma-ray telescopes. The key feature of such Compton telescopes is the high energy resolution that is crucial for high angular resolution and high background rejection capability. The energy resolution around 1 keV is required to approach physical limit of the angular resolution due to Doppler broadening. We have developed a low noise front-end ASIC (application-specific integrated circuit), VA32TA, to realize this goal for the readout of double-sided silicon strip detector (DSSD) and cadmium telluride (CdTe) pixel detector which are essential elements of the semiconductor Compton telescope. We report on the design and test results of the VA32TA. We have reached an energy resolution of 1.3 keV [full-width at half-maximum (FWHM)] for 60 and 122 keV at 0/spl deg/ C with a DSSD and 1.7 keV (FWHM) with a CdTe detector.