CVD diamond for medical dosimetry applications

Diamond is potentially a very suitable material for use as a radiation dosi meter; the wide band gap results in low dark currents and low sensitivity t o visible light, the high carrier mobilities can give rapid response, the v ery high density of strong bonds in the crystal structure make diamond very resistant to radiation damage and it is tissue equivalent. Recent advances in the synthesis of polycrystalline diamond by chemical vapour deposition (CVD) techniques have allowed material with electronic properties suitable for dosimetry applications to be consistently produced. This paper reports on simple dosimeters which have been fabricated from CVD diamond plates wit h Cr-Au electrodes in a sandwich configuration. The performance of the devi ces is compared with a silicon diode dosimeter and a commercial natural dia mond dosimeter in tests using 250 kV X-rays from a clinical source. (C) 200 1 Elsevier Science B.V. All rights reserved.