Response of GSO scintillator to thermal neutrons

A precise measurement was made to investigate the response of a cerium-dope d GSO scintillator to thermal neutrons by means of a plastic scintillator a s a neutron moderator. A delayed-coincidence technique with GSO-plastic sci ntillators was employed for discriminating gamma-rays. The technique was fo und to be very powerful in gamma-ray reduction. In the response spectrum, t hree sharp peaks were observed at 22, 83 and 190 keV. At 250-300 keV the re sponse shows a small bump. This spectral structure was explained by low-lyi ng levels of Gd-156 and Gd-158. Moreover, the response was investigated in terms of time-strength interrelation. (C) 1999 Elsevier Science B.V. All ri ghts reserved.