Traditional semiconductor detectors cannot operate for long periods in high-dose-rate radiation environments. Diamond detectors, with their wide bandgap, high carrier mobility, high radiation hardness, and fast time response, are suitable for radiation detection in extreme environments.

This study aims to investigate the electrical properties, energy resolution, charge collection efficiency, and response characteristics to ⁶⁰Co gamma radiation of single crystal diamond (SCD) detectors.

Initially, the SCD material in the size of 4.5 mm×4.5 mm×0.3 mm from Element Six Ltd. UK was characterized using Atomic Force Microscope (AFM), X-ray Diffraction (XRD) and Photoluminescence Spectroscopy (PL). Subsequently, oxygen-terminated diamond detector was fabricated. Then, the dark current of the detector was measured using a Keithley 4200 Semiconductor Parameter Analyzer, and the energy resolution and charge collection efficiency of the fabricated SCD detector were obtained by comparing them with a silicon detector using a ²³⁸Pu α source. Finally, the response and stability of the SCD detector to ⁶⁰Co gamma dose rates in both current and pulse modes were studied and compared with commercial diamond detector from MICRON, UK.

The detector's electron and hole charge collection efficiencies are as high as 98.9% and 99.2%, respectively, with energy resolutions of 2.54% and 2.86%. The fabricated SCD diamond detector operates in pulse mode and current mode, with gamma dose rate responses ranging from 0.001 3 Gy?h^-1 to 64 Gy?h^-1 and from 0.2 Gy?h^-1 to 64 Gy?h^-1, respectively. The linear correlation can reach over 99.3%, which is superior to the commercial MICRON diamond detector.

Measurement results demonstrate that SCD detector can be applied to real-time gamma dose measurement. Investigating the response of diamond detectors to gamma rays helps to further in-depth research on neutron/gamma-ray discrimination methods based on single-crystal diamond detectors, and can be applied to real-time gamma dose measurement.