Neutron detector development at Brookhaven

Abstract Two-dimensional thermal neutron detectors have been the subject of research and development at Brookhaven for over 20 years. Based primarily on multi-wire chambers filled with a gas mixture containing 3 He, these detectors have been used in wide-ranging studies of molecular biology and material science samples. At each phase of development, experimenters have sought improvements in key parameters such as position resolution, counting rate, efficiency, solid-angle coverage and stability. A suite of detectors has been developed with sensitive areas ranging from 5×5 to 50×50 cm 2 . These devices incorporate low-noise-position readout and the best position resolution for thermal neutron gas detectors. Recent developments include a 1.5 m×20 cm detector containing multiple segments with continuously sensitive readout, and detectors with unity gain for ultra-high rate capability and long-term stability.