A Thin Foil Proton Recoil Spectrometer for DT neutrons using annular silicon detectors

摘要

The use of the Thin-foil proton recoil spectrometer (TPR) to measure DT neutrons has been studied previously [1] and is a well established technique for neutron spectrometry [2]. Recently the TPR spectrometer has been put forward as one of the techniques in the high resolution neutron spectrometer system in ITER [3]. The main focus of this study is to investigate the TPR efficiency and resolution by the use of annular solid state detectors and find near optimal designs for 14 MeV neutron detection from DT plasmas. A Python code was developed for the purpose of calculating efficiency and resolution as a function of spectrometer parameters. The code also calculates the response functions for the selected designs. An optimisation was done regarding the foil thickness, distance from a foil to the detector and distance between detectors using a pareto plot analysis. An investigation was made into how the detector segmentation would influence the spectrometer resolution and efficiency. The results presented include the selected spectrometer design with calculated resolution, efficiency and count rates. The results show that spectrometer efficiency is below 0.01% for resolution better than 5%. Moreover the detector segmentation gives a significant improvement of the spectrometer resolution.