CVD diamond films for radiation detection

Diamond films produced by microwave plasma enhanced chemical vapor deposition (CVD) technique have been used to fabricate radiation detectors. The polycrystalline diamond films have a measured resistivity of 10/sup 12/ /spl Omega/.cm, a carrier mobility of 280 cm/sup 2//V.s and a carrier lifetime of about 530 ps. The detector response to laser pulses (/spl lambda/=355, 532 and 1064 nm), X-ray flux (15-50 keV) and alpha particles (/sup 241/Am, 5.49 MeV) has been investigated. The response speed of the detector is in the 100 ps range. A sensitivity of about 3/spl times/10/sup -10/A/V.(Gy/s) was measured under a 50 keV X-ray flux. The detector current response to X-ray flux is almost linear. It is also shown that CVD diamond detectors can be used for alpha particle counting.>