Characterization of CLYC7 Scintillation Detector in Wide Neutron Energy Range for Fusion Neutron Spectroscopy

The newly developed Cs2LiYCl6:Ce crystal with 7Li-enrichment (CLYC7) scintillators had been utilized as a key component in a compact neutron emission spectrometer (CNES) at the Large Helical Device (LHD). The CNES was employed to enhance understanding the slowing-down process of neutral-beam-injected energetic beam deuterons by measuring the Doppler broadening of beam-driven deuterium-deuterium neutrons. In order to assess the detection capabilities in fusion neutron spectroscopy and to gain understanding into the energy spectrum at various neutron energies, a understanding of the response function of the detector across a wide neutron energy range is essential. Therefore, before implementing the CNES at the LHD, the detector was tested at high-performance neutron source facilities to evaluate its response to both thermal and fast neutrons. The detector exhibited excellent pulse shape discrimination properties. However, it also exhibited complexity through the 35Cl(n,p)35S and 35Cl(n,α)32P reactions in the fast neutron measurement. To emphasize the accuracy and reliability of the detector’s response, particularly in the fast neutron energy range, Monte Carlo N-Particle transport simulations were employed. In order to validate the experimental results against the calculations, an energy-dependent quenching factor was determined. This analysis provided a clear understanding of the CLYC7 scintillation detector and its potential in the context of fusion neutron spectroscopy for applications in the LHD and future fusion devices.