INSTRUMENTS AND METHODS OF EXPERIMENTAL PHYSICS

Study of the influence of light guide type on light collection parameters in scintillation neutron detectors used for diffraction experiments

D. N. Trunov^ab, V. N. Marin^a, R. A. Sadykov^a, E. V. Altynbaev<sup>c

a</sup> Institute for Nuclear Research, Russian Academy of Sciences, Moscow
^b National Research Centre "Kurchatov Institute", Moscow
^c Saint Petersburg State University

Abstract: A comparative study of the influence of the light guide type in neutron scintillation detectors on photon transport parameters has been carried out. A transparent PMMA-based light guide and a polystyrene-based light guide with spectroscopic additives ($PS + 1\% pTP + 0.1\% 3-HF$) were selected for the research. The effect of using an ultra-wide angle lens with purposely increased distortion on the number of photons was also examined. It is shown that the light output of the detector with PMMA-based light guide with light removal at the ends is more than 4 times higher than for the detector based on WLS. For detectors with "fisheye" lenses, the light output differs more than 13 times. In addition, modelling of optical parameters was carried out and a limit on the maximum length of detectors with optically transparent light guide was obtained.

Keywords: neutron detectors, scintillator, spectroscopic fibres, silicon photomultiplier.

DOI: 10.60797/IRJ.2024.149.130