Experimental Study of the Response Functions of Proportional Counters and NE 213 Organic Scintillator for Monoenergetic Neutrons from 80 KeV to 15 MeV

摘要

In this paper, the authors study the response functions of three proportional counters and of two NE 213 type organic scintillators for monoenergetic neutrons in the 80 keV - 15 MeV range. These response functions are used to make deconvolution matrix, which allows the interpretation of experimental results issued of recoil protons method in neutron spectrometry. In a first part these response functions are compared with computed results or with similar works found in the litterature. Generally speaking, perfect agreement does not exist in the case of proportional counters for which in low energy, discrepancy is of about 50%. This deviation is explained by a bad mathematic representation of the physical phenomena acting in the detector. The results are used, in the second part, to obtain neutrons spectra near a reactor and an accelerator. Analysing experimental response functions errors, it is found that the main factor is the uncertainty on the neutron flux absolute measurement, especially for the NE 213 type detectors for which time of flight method allows the elimination of parasite neutrons and of major part of gamma rays. (Atomindex citation 11:500338)