The MULTI spectrometer for measurement of β-decay process in exotic nuclei
Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, 141980 Dubna, Russia
2 Nuclear Physics Institute of the Czech Academy of Sciences, 25068 Řež, Czech Republic
3 National Research Nuclear University, 115409 Moscow, Russia
4 Institute of Nuclear Physics, Almaty, Kazakhstan
Published online: 19 November 2021
The construction of the portable spectrometer, MULTI, is designed for the measurement of β-γ-neutron coincidences on beams of radioactive exotic nuclei. It will be used in measurements of the β-decay process of neutron-rich nuclei with large Qβ values accessible in radioactive beams facilities. The experimental technique includes the measurement of the ratios between gamma-ray emission and multi-neutron emission, following beta-decay of radioactive nuclei implanted into an active target. The construction of a gamma-ray spectrometer based on high-volume CeBr3+NaI(Tl) phoswich scintillation detectors is introduced. Results of the measurements of its fundamental characteristics – total detection efficiency, peak efficiency and Compton suppression effect with a 60Co source are presented. Design of the neutron counter array, consisting of 40 proportional counters filled with 3He gas, was optimized with Monte Carlo simulations. Results were validated with a 252Cf spectroscopic source, leading to expected detection efficiency of ∼35% for neutrons with energy < 1MeV. Further development plans are discussed.
Key words: Monte Carlo simulations / Phoswich detector / gamma-ray spectrometer / 3He neutron counters
© The Authors, published by EDP Sciences, 2021
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