A Raster thermal-neutron scintillation multidetector of modular type

A 100-channel scintillation multichannel detector of thermal neutrons has been designed and manufactured for modernizing the D7a neutron diffractometer on the IVV-2M reactor. The detector is built in accordance with the modular approach and allows arrangement of sensitive surfaces of channels on a cylindrical surface of arbitrary radius. The sensitive volume of a channel is a multilayer composition of stripes of an ND scintillation screen and wavelength-shifting fibers. The dimensions of the entrance aperture of the channel’s sensitive volume are 3 × 120 mm. The average detection efficiency in channels for neutrons of wavelength λ = 1.53 Å is 70%. The gamma sensitivity of the detector channels is no higher than 1 × 10 −7 . The maximum counting rate of an individual channel is ≥ 1 × 10 5 neutrons/s. Each module of the detector is an independent device and contains ten channels for neutron detection, signal-processing electronics, a high-voltage supply system, and computer-interfacing electronics. A CAN interface is used to acquire data from the modules, set the registration parameters, and control the modules.