Undoped InSb Schottky detector for gamma-ray measurements

For measuring X-rays and gamma-rays with better energy resolution and higher efficiency than conventional semiconductor detectors such as Si and Ge detectors, we are studying InSb radiation detectors. Previously, we fabricated p-InSb Schottky type, pn-junction type detectors, and undoped InSb Schottky type detectors with an electrode of 3 mm in diameter, and measured alpha particles of /sup 241/Am. For measuring gamma-rays, we fabricated undoped InSb Schottky type detectors with smaller electrode areas. Gamma-ray signals were clearly separated from the background, and differences between energy spectra of /sup 241/Am and /sup 133/Ba gamma-rays were observed.