Coherent elastic neutrino nucleus scatter response of semiconductor detectors to nuclear reactor antineutrinos

Abstract

We studied the performance of advanced semiconductor detectors to measure reactor antineutrino with the potential to drastically improve efficiency and lower existing thresholds of detectable incident-antineutrino-energy. Recent developments, such as those by the Mitchell Institute Neutrino Experiment at Reactor (MINER) experiment at Texas A&M University, in semiconductor technologies have enabled the ability to lower the coherent-elastic-neutrino-nucleus-scatter (CEνNS) based detection threshold to nuclear recoil energies between 10-eV and 100-eV (Dutta et al., 2016). Existing detectors based on inverse beta decay (IBD) have a threshold of 1.806 MeV (Oralbaev et al., 2016). In this study, we calculated the CEνNS response of semiconductor detectors to antineutrino flux from a 1-MW(th) TRIGA reactor as a function of incident antineutrino energy. In the calculations, the reaction rates of detectors made of germanium and silicon are calculated for a 100-kg detector and placed 10 m from the core. No background radiation characterization and reduction were performed. First, the reactor antineutrino flux spectrum is obtained for the fuel composition specific to 1-MW(th) TRIGA reactor without any thresholds. Next, the standard model (SM) of physics is used to calculate the CEνNS cross-section as a function of incident antineutrino energy. Finally, the above two functions are convolved to provide the detector response for both, germanium and silicon detectors. The results show that germanium has a greater efficiency than silicon; however, it is shown that silicon is sensitive to lower antineutrino energies. It is found that a 100-eV nuclear recoil in germanium semiconductor detectors can be produced by a minimum incident energy of 1.84 MeV antineutrinos, and in silicon by 1.14 MeV antineutrinos. For the lower threshold, a 20-eV nuclear recoil in germanium semiconductors can be produced by a minimum incident energy of 0.82 MeV antineutrinos and in Si by 0.51 MeV antineutrinos. Lowering the detector response energy sensitivity equips us with newer techniques for nuclear fuel monitoring.