Emissions of Hydrogen Isotopes from the Nuclear Muon Capture Reaction in ^natSi

¹ National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan
² Department of Advanced Energy Engineering Science, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580, Japan
³ RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
⁴ Department of Physics, the University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
⁵ Center for Nuclear Study, the University of Tokyo, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
⁶ Research Center for Nuclear Physics, Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka 567-0047 Suita, Japan
⁷ Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan

^* Corresponding author: s-manabe@aist.go.jp

Published online: 26 May 2023

Abstract

The energy spectra of protons, deuterons and tritons produced by the nuclear muon capture reaction in ^natSi were measured at the M1 beam line of Muon Science Innovative Channel (MuSIC) in Research Center for Nuclear Physics (RCNP) using a counter telescope consisting of a Si detector and a CsI(Tl) scintillation detector. The measured energy spectra were consistent with the previous ones. The experimental energy spectra were compared with theoretical model calculations using the Particle and Heavy Ion Transport code System (PHITS). In PHITS, both the dynamical and statistical processes in the nuclear muon capture reaction are described by the Quantum Molecular Dynamics (QMD) or the modified QMD and the Generalized Evaporation Model (GEM), respectively. The PHITS simulation reproduced generally well the measured proton spectrum at emission energies below 20 MeV, while underestimation was seen at emission energies above 20 MeV. The PHITS simulation underestimates remarkably the measured energy spectra of light complex particles (deuterons, tritons, and alpha particles) in the high energy region.