Study for the long-lived gamma background due to neutron emitting calibration reactions

¹ Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Saltlake, Kolkata - 700064, India
² Homi Bhabha National Institute, 2nd floor, BARC Training School Complex, Anushaktinagar, Mumbai- 400094, India

^* e-mail: tanmoy.bar@saha.ac.in

Published online: 3 February 2023

Abstract

In this article, a detailed theoretical investigation has been done on the long-lived gamma background due to neutron emitting reactions. It mainly focused on the experiments that will be used to calibrate energy with the terminal voltage of an upcoming Facility for Research in Experimental Nuclear Astrophysics (FRENA). Many reactions like (p, n), (p, γ) have been utilized in various accelerator facilities around the globe for energy calibration purposes. Neutron emitting reactions like ⁷Li(p, n), ¹³C(p, n), ¹⁹F(p, n), ²⁷Al(p, n), etc. have been very commonly used. For such reactions, a significant number of neutrons produced from such experiments can interact with surrounding elements like copper, tantalum, stainless steel (SS304 and SS316), concrete materials,etc. These interactions may create long-lived gamma activity in the vicinity of the accelerator and detection area. Background gammas from these radioactive isotopes can interfere with gamma measurements in future experiments. The present study has been done to investigate those possibilities of gamma background which may occur due to the calibration study by neutron emitting experiments. Here ⁷Li(p, n), ¹³C(p, n), ¹⁹F(p, n) and ²⁷Al(p, n) reactions having neutron threshold energies 1.8803, 3.2355, 4.2351, 5.8036 MeV respectively are chosen keeping in mind the proton energy available at the facility.