Speaker
Description
Position-sensitive neutron detectors combining spatial, temporal, and spectroscopic capabilities are increasingly demanded for neutron scattering instruments and time-of-flight (ToF) beamlines. We report on a compact neutron Anger camera designed as a proof-of-concept for large-area scintillation-based imaging systems.
The detector employs a 1 mm thick GS20 lithium glass scintillator coupled to a 6 mm boron-free quartz light spreader, with reflective coatings to maximize light collection. Scintillation photons are detected by a custom SiPM matrix of 192 Hamamatsu devices arranged in a 16 × 12 configuration, each with a 6 × 6 mm² active area and 6.1 mm pitch, yielding a 12 × 8 cm² active area. Readout is handled by three FERS acquisition modules performing event-by-event digitization and timestamping via optical links to a central concentrator.
Event localization relies on a center-of-mass algorithm applied to the SiPM light distribution, enabling sub-pixel interpolation into a virtual 320 × 240 pixel image space. Detector characterization was performed with a deuterium-tritium neutron source. Edge-spread function analysis on sharp-edge and slit-mask phantoms yielded an effective spatial resolution of ~0.3 mm, well below the physical SiPM pitch, confirming the Anger reconstruction effectiveness. Images show good linearity and uniformity across the full active area.
Preliminary timing measurements demonstrate a resolution of ~1 ns, enabling ToF-based energy-resolved neutron imaging from pulsed sources. The system supports both integrated and frame-based acquisition modes with online reconstruction.
These results establish SiPM-based Anger cameras as a scalable architecture for high-resolution, spectrally resolved neutron imaging in next-generation instrumentation.