High temperature performances of CVD single crystal diamond detectors

In fusion applications (e.g.Tokamaks) detectors must withstand a very harsh environment characterized by high temperatures and intense radiation fluxes. Conventional solid state detectors (e.g. silicon) cannot be operated at high temperatures and present serious dose limit. Among the possible alternatives to silicon, diamond based detectors are very promising because of their outstanding properties such as radiation hardness, high thermal conductivity and wide band gap. Diamond detectors were proposed as neutron detectors for the Radial Neutron Camera (RNC) and for the Tritium Breeding Module (TBM) of ITER. In the latter the detector working temperature can be up to 400 °C. A few studies, so far have been performed to study the behaviour of diamond detectors at high temperatures. In the present paper the performances of single crystal diamond detectors operated at high temperatures are reported. An innovative detector layout was studied which is based on a mechanical contact avoiding the use of critical components such as glue, welding, etc. A 500 μm thick single crystal diamond plate with platinum electrical contacts was tested reaching temperatures up to 240 °C, its I-V and C-V characteristics were measured at increasing temperatures. The results demonstrated that the proposed innovative layout presents very interesting behaviour and stable response at high temperatures. Furthermore, a commercial detector was tested at temperatures up to 180 °C while operated in current mode using a beta source. The signal to noise ratio vs.Temperature resulted acceptable up to about 170 °C. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence.