Performance of four CVD diamond radiation sensors at high temperature
Authors
Fern, GR; Hobson, PR; Metcalfe, A; Smith, DR
Abstract
Ionising radiation detectors based on wide band-gap materials have the potential to operate at temperatures higher than 200°C. Such detectors are important in applications such as monitoring near nuclear reactors and in deep oil and gas well borehole logging. We discuss the development of alpha particle detectors, based on CVD diamond, which operate with high charge collection efficiency and energy resolution at temperatures up to 225°C. Four nominally identical commercial, electronic grade, CVD diamonds have been coated with a thin metal conductive layer in our laboratory and then attached to ceramic PCB. We present the I–V characteristics, the charge collection efficiency and the energy resolution for alpha particles from a mixed 239Pu,241Am,244Cm source, for the four sensors operating at temperatures from 20 to 250°C. Monte Carlo simulations of the energy spectra and charge collection efficiency and experimental measurements of these are presented. Energy resolutions between 1.6% and 4.0% at elevated temperatures with charge collection efficiency exceeding 96% were measured. The potential for thermal neutron detection is discussed.