Abstract: High quality (100)-oriented diamond film was prepared by Microwave Plasma Chemical Vapor Deposition (MPCVD) with thickness of 100μm. A α-particle detector was successfully made on the prepared film. The charge collection efficiency is 37.7% under -100V bias in average while the maximum reaches 60%. On the basis of this, diamond neutron detector is successfully developed by evaporating a layer of 10B converter with a proper thickness on the surface with an evidently increased response to α particle. At the electric field of 1V/μm, the energy resolution is 9.3%, the detecting efficiency to 252Cf neutron is 1.67%. Electric field and converter thickness have influences on the detecting efficiency. With the converter thickness increasing, the detecting efficiency increases, when the thickness reaches 1.5μm, the deteting efficiency turn to decrease.

Key words: diamond film, radiation detector, photoelectrical properties