Scalability of Gadolinium-Doped-Water Cherenkov Detectors for Nuclear Nonproliferation

Antineutrinos are an inextricable element of the fission process. The kiloton-scale KamLAND experiment has demonstrated a capability to detect reactor antineutrinos at range few hundred kilometers. But or rule out existence single small over many kilometers requires large detector, so in fact that optical opacity detection medium itself becomes important factor. If detector is photons cannot traverse then it impractical. For this reason, gadolinium-doped-water Cherenkov detectors have been proposed for volumes, due their appealing light-attenuation properties. Even though emission does not produce and energy resolution poor, there may be place Gd-doped-water far-field nuclear-reactor monitoring. In paper, we focus on reactor-discovery potential large-volume nuclear-nonproliferation applications. Realistic background models worldwide flux, geoneutrinos, cosmogenic fast neutrons, detector-associated backgrounds included. We calculate run time required 50-MWt variety stand-off distances as function size. highlight that, present, photomultiplier-tube dark rate event reconstruction algorithms limiting factors extending such beyond fiducial mass approximately 50 kt.