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 metalsemiconductor 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 oC, 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.