Measurement of deuteron- and proton-induced lithium reaction cross sections for SLICS detector efficiency calibration

Abstract

The Short-Lived Isotope Counting System (SLICS) was developed identify and count beta decays of product nuclei produced by light-ion reactions generated with high-power short-pulse lasers using inertial confinement fusion (ICF) or target normal sheath acceleration (TNSA). An experiment was performed in 2024 to measure the efficiency of this detector by creating a known amount of 8Li at a point in front of the detector, then counting the resulting number of detected beta decays. Unfortunately, previous measurements of the 7Li(d, p)8Li, 7Li(p, α)4He, and 6Li(d, α)4He cross sections needed to predict the amount of 8Li vary widely. To address this problem, an experiment was carried out using the SUNY Geneseo Pelletron in which 1.1 MeV, 1.3 MeV and 1.5 MeV protons and deuterons were incident on a self-supporting 116 nm thick gold foil coated with thin layer of natural lithium. The elastic scattering from the gold, 6Li and 7Li yielded the beam current, and 6Li and 7Li thickness, respectively. Measurement of charged particle energy spectra at angles of 40, 60, 90, 120, 140, 160, and 166 allowed the relevant cross sections to be determined. This material is based upon work supported by the Department of Energy [National Nuclear Security Administration] University of Rochester “National Inertial Confinement Fusion Program” under Award Number(s) DE-NA0004144.