Single Crystal Diamond Detector for gamma dose measurement

Traditional semiconductor detectors cannot operate in high dose rate radiation environments for a long time. Diamond detectors have the advantages of large bandgap width, high carrier mobility, strong radiation resistance, and fast time response, making them suitable for radiation detection in extreme environments. This article describes the preparation of a high-performance oxygen terminated single crystal diamond detector (4.5 × 4.5 × 0.3 mm3) and investigates its electrical properties, energy resolution, charge collection efficiency, and 60Co γ radiation response characteristics. The results indicate that the prepared single crystal diamond detector has a low dark current of 0.26 pA/mm2 under a bias voltage of 150V. The charge collection spectrum of the detector was tested using a 238Pu α source irradiation, and the results showed that the electron and hole charge collection efficiencies of the detector were as high as 99.2% and 98.8%, respectively, with energy resolutions of 2.87% and 2.53%, respectively. The prepared single crystal diamond detector operates in pulse mode and current mode with lower limits of gamma dose rate response of 0.0013 Gy · h-1 and 0.2 Gy · h-1, respectively. When the response lower limit reaches 64 Gy · h-1, the linear correlation of the detector can reach over 99.3%, and the response lower limit is better than that of commercial diamond detectors abroad. Studying the response of diamond detectors to gamma rays is helpful for further in-depth research on neutron/gamma ray discrimination methods based on single crystal diamond detectors and their application in real-time gamma dose measurement.