Energy Spectrum Assessment of NaI(Tl), NE113, and NE213 Scintillators in Very Low-Energy Fusion Studies

In the study of very low-energy fusion reactions, where the cross section drops by many orders of magnitude, measuring the fusion products with minimal uncertainties and free from natural background interference is quite challenging. The present work focuses on qualitative and quantitative assessment of NE113 plastic scintillators, NE213 liquid scintillators, and NaI(Tl) detectors for such studies. All scintillator detectors are calibrated using standard gamma sources , , and and are compared with Geant4 Monte Carlo simulations. A gamma spectrum and neutron unfolding procedure is developed for these detectors with the help of these simulations. To verify this method, an experiment was performed to measure the fusion products from deuteron-deuteron fusion reactions induced by a 10-keV beam on a Zr metallic hydride environment. The results show that the NE113, NE213, and NaI(Tl) scintillator detectors, along with the developed gamma spectrum unfolding procedure, can qualitatively analyze complex gamma spectra with reasonable accuracy.