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Description
Modular neutron spectrometer (MONES) in ACCULINNA-2 based on stilbene crystals in combination with 3-inch fast ET-Enterprise 9822B photomultipliers, was developed in accordance with the requirements of our recent research in studying the low-energy spectra of several unbound nuclear systems 10Li, 5–7H, 7,9He populated in transfer reactions [1–3]. Since the correlation between the incident neutron energy and the amplitude scintillator response is unsettled, the time of flight (TOF) method is routinely applied for neutron energy measurements. The neutron energy is obtained from the measured neutron flight time using the nonrelativistic kinetic energy equation and its accuracy is entirely determined by the time resolution of scintillation detector. This work is devoted to the characterization of neutron TOF spectrometer, in terms of amplitude and time resolution, neutron/gamma separation performance and detection efficiency in the detector. The detector response to gamma-rays and neutrons were performed using Monte Carlo Geant4 simulations and compared with measured data. The first derivative of measured response by the use of gamma sources was to locate the Compton Edge position for amplitude calibration. The portable generator of “tagged” neutrons with energies of 14.1 MeV [4] was utilized for reconstruction the light out response to heavy ions (protons and alpha particles) and determining the neutron registration efficiency.
[1] A. A. Bezbakh et al., “Study of 10Li low energy spectrum in the 2H(9Li, p) reaction”, Bulletin of the Russian Academy of Sciences: Physics 84, 491, 2020.
[2] I. A. Muzalevskii et al., “Resonant states in 7H: Experimental studies of the 2H(8He,3He) reaction”, Physical Review C, 103, 044313, 2021.
[3] M. S. Golovkov et al., “Observation of a positive-parity wave in the low-energy spectrum of 7He”, Physical Review C, 109, L061602, 2024.
[4] N. Ruskov et al. “TANGRA-Setup for the Investigation of Nuclear Fission induced by 14.1 MeV neutrons”, Physics Procedia 64, 2015.
