New high-flux and high-brilliance neutron sources demand a higher count-rate capability in neutron detectors. In order to achieve that goal, the Solid-State Neutron Detector (SoNDe) project is developing a scintillation-based neutron detector. It will be capable of fully exploiting the available flux at small-angle neutron scattering (SANS) instruments at high brilliance sources, such as SKADI at the European Spallation Source (ESS). The read-out of the scintillator is based on a pixelized multi-anode PMT (MaPMT), where each pixel is treated separately. In addition to enabling higher achievable count-rates, one of the design goals was to develop a modular and scalable solution that can also be used in other instruments or even contexts, such as for laboratory setups. This has been achieved by combining the complete read-out electronics along with the MaPMT into modules that can be controlled and read-out individually via a network without additional any infrastructure. An overview of the present state of development and current test results is presented, highlighting the results of previously published project reports.

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Abstract-During the upgrade of the small-angle neutron scattering instrument KWS-1 at the research reactor FRJ-2, the 15-yr-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 aiming at counting rates of several hundred kilohertz. The whole detector system has been recently installed at KWS-1 and measurements to study the system performance have been carried out. The linearity and spatial resolution of the new detector have been determined by an analysis of an acquired image taken with a hole diaphragm in front of the scintillator. The overall system dead time has been measured by comparing the detector count rates at several scattering intensities to the count rates achieved with a fission chamber. Finally, scattering patterns of well-known samples have been taken in order to demonstrate the quality of the acquired images.

Abstract-A new two-dimensional position-sensitive detector system for small-angle neutron scattering experiments is under development. It is based on a 60 60 cm 2 large 6 Li-glass scintillator for the neutron capture and dispersion of the emitted light on an array of photomultiplier tubes for the derivation of the event position. For subthermal neutrons of 8 Å, an efficiency of 96% and a spatial resolution of 8 mm are to be achieved. Major improvements have been made in the signal-and data-processing branch, which aims at an electronical dead time of 1 s. A fast digitalization method using free-running analog-to-digital converters for each photomultiplier combined with field-programmable gate arrays for a parallel event detection in all channels has been applied. A subsequent farm of up to 16 floating-point digital signal processors is used to provide enough computing power for an improved reconstruction of the event position according to a maximum likelihood method.