Optical detection of neutrons with silicon photomultipliers (Conference Presentation)

Beyond its obvious use for radiation monitoring, low-energy (thermal) neutron detection finds applications in road paving, hydrocarbon prospecting, hydrology, agronomy and planetary exploration.All known techniques are based on amplification of exothermic neutron absorption reactions with particular isotopes, especially helium-3. We have invented compact, low-voltage/power detectors based on optical scintillation of noble gases induced by energetic fragments of neutron absorption by boron-10. The primary scintillations occur in the ultraviolet (UV) and far-UV spectral regions, and wavelength-shifting materials are used to transform them into light that can be detected by silicon photomultipliers (SiPMs). SiPMs' light footprint facilitates cellular networks of diverse compact directors for momentum and energy resolution of neutron fields. We have built a thumb-size submersible detector and used it for in-situ neutron dosimetry in a water phantom at a proton therapy facility.