Study of fast radiation-detectors based on fast halide scintillator crystals and their application to the CERN n_TOF experiment

Abstract

The inorganic scintillator detectors are widely used in nuclear experiments. New advances on the development of such detectors make it necessary a continuous review of new materials and photosensors. In this work, four fast scintillator crystals based on halide materiaIs: a 18x18x25 mm3 CeBr3, a 18x18x25 mm3 Csl(Na) and two CeF3 of, respectively, 18x18x40 mm3 and 18x18x50 mm3, coupled to fast photomultiplier tubes, R7600U-200 and a PIN diode, have been characterised using both spectroscopic and pulse shape analysis techniques. A specific electronics associated, a preamplifier and a shaper, have been developed. These radiation detectors have been characterised in the n_TOF facility at CERN by the prompt gamma-rays emitted from neutron-capture reactions {n, gamma) for the isotopes 197Au and natAg, proving so the ability of these fast detectors to work in a such background. The prompt gammas from the 235U{n,f) reaction were detected in coincidence with gaseous detectors, the PPAC chambers, for neutron kinetic energies ranging from a few eV to several keV. Furthermore, the g-flash arriving to the nTOF experimental areas produced by the CERN-PS pulsed proton beam when impinging in the nTOF spallation target, was studied at both EAR-1 and EAR-2, after passed by the neutron-beam pipes of, respectively, 200 m flight path in horizontal and 20m flight path in vertical.