Multi-ring position-sensitive detector for registering small-angle neutron scattering

A position-sensitive detector for the YuMO time-of-flight small-angle neutron scattering spectrometer at the IBR-2 pulsed reactor (Dubna, Russia) is proposed. Position sensitivity is realized by determining the polar and radial components of the scattering vector. The detector consists of eight independent 3He annular counters with high-resistance wires lying in one plane and occupying the same gas volume. To determine the coordinates, the charge division method is used. The signals from both ends of the wire are picked up by charge-sensitive preamplifiers and digitized by an analog-to-digital converter (ADC) with a fixed dead time. The VME-standard TMS320C40-based processor block of the data acquisition system is responsible for determining the coordinates and accumulating spectra. The preliminary results of the tests of the detector are presented.