CVD DIAMOND FILMS FOR RADIATION DETECTION

Diamond films produced by microwave plasma enhanced chemical vapor dep osition (CVD) technique have been used to fabricate radiation detector s. The polycristalline diamond films have a measured resistivity of 10 (12) OMEGA.cm, a carrier mobility of 280 cm2/V.s and a carrier lifetim e of about 530 ps. The detector response to laser pulses (lambda = 355 , 532 and 1064 nm), X-ray flux (15 - 50 keV) and alpha particles (241A m, 5.49 MeV) has been investigated. The response speed of the detector is in the 100 ps range. A sensitivity of about 3 x 10(-10) A/V.(Gy/s) was measured under 50 keV X-ray flux. The detector current response t o X-ray flux is almost linear. It is also shown that CVD diamond detec tors can be used for alpha particle counting.