Performance measurements of a new large area neutron scintillation detector system

During the upgrade of the small angle neutron scattering instrument KWS-1 at the research reactor FPJ-2, the 15 years old detector system has been replaced. While the Anger camera based concept of the detector remained unchanged the signal and data processing branch has been completely revised. Because of higher count rate requirements, a highly configurable parallel readout electronics has been developed. It aims at counting rates of several 100 kHz and is based on free running ADCs with FPGAs for a parallel digital pulse processing and an embedded DSP farm for the position reconstruction. The whole detector system has been recently installed at KWS-1 and measurements under real operation conditions have been carried out. This paper reports on the first results, achieved for detector linearity, position resolution, system dead time and the quality of the acquired images.