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

Resumo

The inorganic scintillator detectors are widely used in nuclear experiments. New advances on the development of such detectors make necessary a continous review of new materials and photosensors. In this work, four fast scintillator crystals based on halide materials: a 18x18x25 mm3 CeBr3, a 18x18x25 mm3 CsI(Na) and two CeF3 of 18x18x40 mm3 and 18x18x50 mm3 , coupled to fast photomultiplier tubes, R7600U-200 and a PIN diode, both from Hamamatsu , have been characterised using spectrospic and pulse shape analysis techniques. The electronic assosiated, a preamplifier and shaper have been developed. These radiation detectors have been characterised by the prompt gamma-rays emmited from neutron induced reactions: neutron capture for 197Au(n,g) and natAg and (n,g) and neutron induced fission, 235U(n,f), in coincindence with a gaseous detector, PPAC chamber, in the n_TOF experiment at CERN, a facility designed to study neutron-nucleus interactions for neutron kinetic energies ranging from a few meV to 1 GeV, based on a pulsed neutron source coupled to both a 200 m flight path and a vertical 20m flight path. The neutron kinetic energy is determined by time-of-flight. Besides this, the g-flash at the CERN-n:TOF facility have been studied at both experimental areas.