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 1012 Ω.cm, a carrier mobility of 280 cm2/V.s and a carrier lifetime of about 530 ps. The detector response to laser pulses (λ = 355, 532 and 1,064 nm), X-ray flux (15--50 keV) and alpha particles (241Am, 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 to X-ray flux is almost linear. It is also shown that CVD diamond detectors can be used for alpha particle counting