CVD diamond films for radiation detection

Abstract

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.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>