Abstract

An intercomparison of the performances of active neutron detectors was carried out in pulsed neutron fields in the new HiRadMat facility at CERN. Five detectors were employed: four of them (two ionization chambers and two rem counters) are routinely employed in the CERN radiation monitoring system, while the fifth is a novel instrument, called LUPIN, specifically conceived for applications in pulsed neutron fields. The measurements were performed in the stray field generated by a proton beam of very short duration with momentum of 440 GeV/c impinging on a dump. The beam intensity was steadily increased during the experiment by more than three orders of magnitude, with an H*(10) due to neutrons at the detector reference positions varying between a few nSv per burst and a few mu Sv per burst, whereas the gamma contribution to the total H*(10) was negligible. The aim of the experiment was to evaluate the linearity of the detector response in extreme pulsed conditions as a function of the neutron burst intensity. The results show that the ionization chambers have a quasi-linear response, very close to the ideal behaviour also for values of H*(10) of a few mu Sv/burst; the LUPIN response shows a slight deviation from the ideal curve when the H*(10) per burst is higher than 100 nSv; the rem counters response are characterized by a strong deviation from the linearity for H*(10) values higher than a few tens of nSv. (C) 2013 Elsevier Ltd. All rights reserved.

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