X-ray and electrical characterization of a multipixel diamond-based detector in high temperature environments

An 8-pixel X-ray diamond detector prototype, fabricated on an alumina substrate and specifically designed to operate at high temperature, has been developed and tested. Tungsten electrodes were developed as metal-semiconductor contact and showed an ohmic behavior, as inferred from current-voltage measurements. A 40-cycles thermal stress test performed in helium atmosphere, in which temperature has been varied cyclically between 100 and 240 °C, showed minor evolution of the detector dark current, presumably related to progressive water desorption from the alumina substrate. Conversely, X-ray photocurrent measurements showed no significant differences before and after the thermal cycles, confirming no degradation of the stability of the prototype even after prolonged operation at high temperature.