Speaker
Description
The China Spallation Neutron Source (CSNS) is a multidisciplinary user facility requiring large quantities of position-sensitive neutron detectors for scattering and imaging instruments. To mitigate the global shortage and cost of 3He, CSNS has developed and deployed multiple generations of large-area scintillator neutron detectors.
The first-generation system uses 6LiF/ZnS(Ag) scintillation screens coupled to crossed wavelength-shifting fiber (WLSF) arrays and multi-anode photomultiplier tubes (MA-PMT). This flat-panel detector has been routinely operated at the General Purpose Powder Diffractometer (GPPD) since 2018, providing a typical pixel size of 4×4mm2 and stable performance for diffraction measurements.
To improve efficiency and scalability, a second-generation “louver” detector was developed using oblique 6LiF/ZnS(Ag) scintillator screens with silicon photomultiplier (SiPM) readout. This design has been implemented for the Engineering Materials Diffractometer (EMD) and the Energy-Resolved Neutron Imaging instrument (ERNI), achieving a total active area exceeding 6 m2. The louver geometry increases the effective converter thickness, improving the efficiency from ~38% to ~62% at 1.4 Å, and supports elongated pixels (e.g., 3 mm × 50 mm and 3 mm × 200 mm) tailored to instrument needs.
A third-generation scintillator detector is under development to reach sub-millimeter spatial resolution for single-crystal neutron diffraction. Current R&D focuses on compact optical coupling, optimized photosensor arrays, and scalable readout electronics for future CSNS instruments.