Eur. Phys. J. A (2018) 54: 82
https://doi.org/10.1140/epja/i2018-12519-1

Regular Article - Experimental Physics

Testing of a sCVD diamond detection system in the CROCUS reactor

¹ NES/LRS, Paul Scherrer Institute (PSI), CH-5232, Villigen PSI, Switzerland
² LRS, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
³ CIVIDEC Instrumentation, Wien, Austria
⁴ Vienna University of Technology, Wien, Austria

^* e-mail: mathieu.hursin@psi.ch

Received: 25 January 2018
Accepted: 24 April 2018
Published online: 24 May 2018

Abstract

The paper describes the testing of the NEUTON detection system into CROCUS, the zero-power reactor of the École Polytechnique Fédérale de Lausanne (EPFL). NEUTON is composed of a mm sCVD diamond detector with a ⁶Li converter and the associated acquisition electronics. It is developed by CIVIDEC Instrumentation GmbH. The use of a diamond detector with converter in the mixed radiation field of a nuclear reactor is challenging because these detectors are sensitive to gamma-rays, fast neutrons and thermal neutrons through conversion in ⁶Li . In NEUTON, the rejection of gamma-rays is achieved in real time, via the analysis of the signal pulse shape from the detector. To do so, a few signal characteristics (amplitude, area and FWHM) are recorded in the integrated Field Programmable Gate Arrays (FPGA) of the system. This treatment does not induce any dead time. Measurements in CROCUS demonstrated for the first time the capability of a system like NEUTON to detect and separate fast neutrons, thermal neutrons, and gamma-rays. The system response was shown to be linear with respect to the reactor power (up to 35W) and its thermal sensitivity was found to be cps/nv.