Spectrometric properties of the CVD diamond detector for measurement of the ‘lost alpha particles’

Abstract

Measurement of energy of the ‘escaping alpha particles’ from the thermonuclear reaction in the tokamak is important to get information on the energetic balance in future thermonuclear reactors producing electrical energy. Detectors will work in a harsh environment (high fluxes of particles, high temperature). Synthetic (CVD) diamond can be used in this case as a semiconductor detector. Tests with such a detector are described. Energy calibration has been carried out with a triple alpha particle isotopic source, 239Pu, 241Am, 244Cm (PAC), with the α energy peaks at ca. 5.2, 5.5 and 5.8 MeV. A very good energy resolution has been obtained, comparable with the resolution of the classic silicon detector. Energy response has been also investigated with the use of monoenergetic alpha particle beams (0.4 to 2 MeV) from the Van de Graaf accelerator. The amplitude linearity of the signal is very good, including besides results of measurements with the PAC source.