Design consideration for high-energy-resolution neutron spectrometer based on associated particle detection using proton recoil telescope and time-of-flight technique for ITER

For ion temperature measurement in the ITER high power operation phase, we propose a promising high-energy-resolution neutron spectrometer based on the associated particle detection using a proton recoil telescope and a time-of-flight spectrometer. To verify the operational principle and the basic performance of this system, we have set up a prototype system through Monte Carlo simulations and carried out a preliminary experiment with a deuterium-tritium (DT) neutron beam at the Fusion Neutronics Source, JAEA. The results have demonstrated that the energy resolution could be achieved around 3.3% (in full width at half maximum) for DT neutrons. In addition, the design consideration of this system for an application to ITER is given on the detection efficiency, the applicable range in the ITER operation, and the detector lifetime