Usability of diamond detectors for spectrometric measurements of lost alpha particles

Measurement of energy of the lost alpha particles (‘escaping alpha particles’) from the thermonuclear reaction in the tokamak is important to obtain information on the energetic balance in future thermonuclear reactors which will be used in power plants. A synthetic high purity CVD monocrystalline diamond detector has been tested in aspect of its potential application for spectrometric diagnostic of the lost alphas of which maximum energy from the thermonuclear reaction is equal to 3.5 MeV. Spectrometric properties of the diamond detector (Diamond Detector, Ltd.) of the 50 μm thickness have been performed using alpha particles of defined energies. The energy calibration and the study on the energy resolution have been carried out using a triple alpha particle isotopic source AMR33 ( 239Pu + 241Am + 244Cm) with the alpha energy peaks at ca. 5.2, 5.5 and 5.8 MeV, the ( 212Bi + 212Po) isotopic source of energy 6.0 and 8.7 MeV and a van de Graaff accelerator delivering a well defined monoenergetic alpha beam, changed between 0.4 and 2 MeV. A 14 MeV neutron generator has been employed as a source of alpha particles from D–T reaction accompanied by another induced radiation to test the behaviour of the diamond detector under such conditions. ► High resolution of diamond detector signal. ► Good linearity in a wide range of alpha particle energies. ► Very good spectrometric characteristic for the use for measurements of the lost alpha particles.