Neutron-Detection Materials and Structures Enabled by Photopolymerisation: Converter Loading, Light Collection and Discrimination

Additive manufacturing can place neutron-conversion materials and scintillating volumes into geometries that are difficult to machine, but the response of a neutron detector depends on more than converter loading. A neutron must interact in the converter, reaction products must deposit useful energy in the scintillating region, generated photons must reach the photosensor, and the event must be discriminated from gamma-ray and other backgrounds. This review treats those stages separately and focuses on photopolymerisation-compatible routes while using adjacent additive-manufacturing evidence when it defines the detector physics. Fast-cured organic scintillator formulations have demonstrated neutron-gamma pulse-shape discrimination; boron-loaded fast-cured plastics demonstrate thermal-neutron-sensitive chemistry; and 3D-printed lithium-6-containing scintillator structures illustrate how spatially designed converter distributions can support event discrimination. The engineering conclusion is that converter mass fraction alone is an inadequate optimisation variable. Required reporting should connect isotope, chemical form, particle size, spatial distribution, optical attenuation, scintillation yield, event-selection method, neutron spectrum, gamma background and geometry. ER-424.