Finding Trafficked Radiological Materials via Coherent Elastic Neutrino-Nucleus Scattering

The potential to use neutrinos for nuclear non-proliferation has been heavily debated due to the tension between production abundance and low interaction rate. A newly detected neutrino interaction channel, coherent elastic neutrino-nucleus scattering (CE$\nu$NS), could potentially end this debate due to its improved cross-section compared to other neutrino interactions. This paper presents a feasibility study for the use of CE$\nu$NS superconducting detectors to find trafficked radiological materials. To do this, we calculated the minimal activity required for situational detection under ideal conditions, without background, at 95% confidence level. This analysis was performed for four commonly smuggled radioisotopes: $^{137}$Cs, $^{109}$Cd, $^{192}$Ir, and $^{57}$Co. Using these results, we conclude that CE$\nu$NS could be used to discover trafficked $^{137}$Cs sources with an activity above the PBq level, but that it is not applicable for finding other radioactive sources. This framework can also be applied to other nuclear security concerns, such as safeguarding generation IV nuclear reactors.