  Multiple types of high quality neutron detectors are proposed for the first
phase of the China Spallation Neutron Source (CSNS), which will be commissioned
in 2018. Considering the shortage of 3He supply, a detector module composed of
49 boron-coated straws (BCS) was developed by Proportional Technologies Inc.
(PTI). Each straw has a length of 1000 mm and a diameter of 7.5 mm. Seven
straws are tightly packed in a tube, and seven tubes are organized in a row to
form a detector module. The charge division method is used for longitudinal
positioning. A specific readout system was utilized to output the signal and
simultaneously encode each straw. The performance of this detector module was
studied using a moderated 252Cf source at the Institute of High Energy Physics
(IHEP). The signal amplitude spectrum indicates its n-gamma discrimination
capability. Despite the complex readout method, a longitudinal resolution of
6.1-0.5 mm was obtained. The three-dimensional positioning ability qualifies
this BCS detector module as a promising neutron scattering spectrometer
detector.
