Room temperature gamma ray detectors are the cornerstone of many radiation detection and imaging systems in various fields, such as medical imaging, nuclear security, scientific research and so on. Compared to scintillators, the semiconductor gamma ray detector has the advantage of intrinsically high energy and spatial resolution. However, after decades’ research and development of various candidate semiconductors, CdZnTe is the only commercial semiconductor gamma ray detector.
Berkeley Lab’s Nuclear Science Division hosted a launch event for the U.S. 2023 Long Range Plan for Nuclear Science on Friday, October 6, one of over 20 simultaneous events held across the country at various Nuclear Science Advisory Committee (NSAC) participating organizations.
In 2013, researchers carried a Microsoft Kinect camera through houses in Japan’s Fukushima Prefecture. The device’s infrared light traced the contours of the buildings, making a rough 3D map. On top of this, the team layered information from an early version of a hand-held gamma-ray imager, displaying the otherwise invisible nuclear radiation from the Fukushima Daiichi Nuclear Power Plant accident.
For decades, the LBNL Semiconductor Detector Lab (SDL) has been at the forefront of advancements in gamma-ray detector technology. Amongst the technologies pioneered at the SDL are double-sided high-purity germanium (HPGe) strip detectors with amorphous germanium (a-Ge) contacts  (Fig. 1). These devices find application in a range of areas including basic science, nuclear security, medical imaging, and gamma-ray astronomy. Using this technology, SDL researchers have designed, developed, and built detectors for multiple instruments for astrophysics projects led by the Space Sciences Laboratory at UC Berkeley . These include the Compton Spectrometer and Imager (COSI) [3-6] and the Gamma-Ray Imager/ Polarimeter for Solar Flares (GRIPS) [7-9], which were successfully flown on balloon missions for NASA.