A new concept of 2D scintillation detector for thermal neutrons based on a light sharing approach

In this new concept of 2-dimensional scintillation detector, the detector consists of an almost gapless assembly of individual and optically isolated ZnS/⁶LiF bars with embedded and uniformly distributed WLS fibers running from one end of the bar to the other. The longitudinal position is determined from the left-right asymmetry of the number of photons detected on both sides of the fibers while the transverse position is simply given by the transverse position of the bar. Special Y11(400)M WLS fibers with different attenuation lengths ranging from 13 cm to 30 cm have been developed by Kuraray for this specific application. Two different detection units have been built. Their performance in a neutron beam are presented and compared with simulation results.