Development of a Large-Area ³He Tube Array Neutron Detector with Frequency Reduction Capability

The Time-of-flight high-resolution neutron diffractometer (TREND) at the China Spallation Neutron Source (CSNS) has been successfully equipped with a large-area 3 He tube array neutron detector, designed to achieve exceptional resolution and uniformity. The detector system, comprising 14 Banks and 134 modules with 1376 3 He tubes, is optimized for high-angle and medium-to-low-angle measurements. Advanced dual-end readout electronics ensure precise charge and time-of-flight measurements, while rigorous performance testing confirmed the system's spatial resolution and uniformity. In-situ testing using polyethylene samples validated the detector's operational stability, with counting rate deviations within 3.7%. The system also demonstrated excellent two-dimensional imaging capabilities and adaptability to various neutron wavelength ranges through harmonic division techniques. These results highlight the TREND detector system as a robust and versatile tool for high-resolution neutron diffraction studies.