Speaker
Description
Diamond detectors are increasingly adopted for fast neutron measurements thanks to their excellent timing resolution, radiation hardness, and low noise. In a dedicated measurement campaign at the ISIS spallation source, we implemented a full digital acquisition chain based on a 500 μm thick single-crystal diamond detector, broadband preamplification, and the CAEN DT5751 digitizer (10-bit, 1–2 GS/s). The system acquired synchronized waveforms from the neutron beam and accelerator trigger, enabling nanosecond-precision time-of-flight (ToF) analysis.
Each recorded event was processed to extract both ToF and pulse integral, generating biparametric ToF–energy spectra that revealed distinct neutron interaction channels, including elastic scattering and inelastic (n,α) and (n,3α) reactions on carbon. The setup resolved the dual-bunch beam structure of ISIS and discriminated prompt gamma flashes from neutron signals via energy thresholding. The acquisition chain, fully digital and compact, demonstrated the capability to characterize fast neutron beams with high accuracy, without relying on analog shaping or external timing modules.
Building on this approach, CAEN has developed new instrumentation—such as the DT2751 digitizer with 16 channels at 1 GS/s sampling , 14-bit and an open FPGA architecture—which allows implementation of advanced real-time processing algorithms. These new tools are fully compatible with the measurement technique demonstrated in this work and offer enhanced flexibility and performance. In particular, they open the way to apply waveform-based ToF–energy spectroscopy with diamond detectors to neutron diagnostics in fusion plasmas, where high timing resolution and compact form factors are essential.
