Neutron measurements with lanthanum-bromide scintillation detectors - A first approach

In this paper we report on the measurement of gamma-rays with a 2in. x 2in. LaBr3:Ce scintillation detector. The gamma-rays were emited in the spontaneous fission of Cf-252 and the reaction U-235 (nth,f), respectively, and detected in coincidence with fission fragments. After presenting some of the properties of the detector, we show how well gamma-rays produced in different reactions may easily be distinguished by their characteristic time-of-flight. Then we focus on the analysis of gamma-rays from inelastically scattered neutrons in the scintillation crystal and demonstrate how this information may be used for neutron spectroscopy. We determine the neutron detection efficiency and compare it to the result of calculations based on existing reaction cross sections. We also give a first example for an application, where the spectrum of fission neutrons is assessed. Finally, we discuss the detection performance in relation to other detector systems, commonly used for neutron monitoring.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard