A microwave-based gamma-ray detector

This paper presents a contactless, microwave-based gamma ray detector for detecting low-energy gamma ray photons. The detection is based on a microwave cavity perturbation method, and uses a reflection-type cavity resonator with a detector-grade CZT crystal. The reflected power from the cavity is measured and this monitors the changes in the photoconductivity of the CZT crystal in the presence of a gamma-ray. A gamma ray detection sensitivity of <; 100 keV is achieved at room temperature. The proposed system can be used in homeland security or radioactive material characterization applications.