Development of 17N as a time-tagged neutron source for calibration of large antineutrino detectors

Abstract

Large antineutrino detectors hold the potential for remote nuclear reactor monitoring and discovery, which is of great interest for nonproliferation and treaty verification applications. Correlated-particle calibration sources are especially useful for large-volume designs based on detection of inverse beta-decay events, as the timing information of the coincident particles improves background rejection and event reconstruction. 17N is a promising calibration source since it emits beta-correlated delayed neutrons and can be produced relatively easily using high-energy neutrons. In this work, we examine the feasibility of 17N as a time-tagged calibration source for large antineutrino detectors. 17N was produced using a DT neutron generator from a water sample enriched in 17O, and the observed production rates were found to be consistent with previous measurements of the 17O(n,p)17N reaction cross-section. Time-tagging of 17N delayed neutrons is demonstrated via beta-neutron coincidence measurements conducted using a specialized beta detector.