Investigation of basic characteristics of synthetic diamond radiation detectors

Diamonds have attractive properties for use as radiation detectors. Recent advances in diamond fabrication techniques have made it possible to produce almost perfect single crystal materials that have electrical properties suitable for radiation detectors. We therefore developed detectors made of high-purity synthetic IIa diamonds grown by a high-pressure, high-temperature method and investigated their basic properties. These detectors have Schottky and Ohmic electrodes, and the leakage current is less than 20 pA with reverse bias voltages up to 2.4 kV, demonstrating that the detector withstands high bias voltage. The results of testing the electrical properties show that the electrodes work well. The best detector achieved an energy resolution of 15.4 keV (FWHM) for 5.486 MeV alpha particles from ²⁴¹Am.