Data Reduction and Analysis with the MPRu instrument for Neutron Emission Spectroscopy at JET

Abstract: This research project centres on advancing data analysis techniques using the Magnetic Proton Recoil Upgrade Neutron Spectrometer (MPRu) for neutron emission spectroscopy during the deuterium tritium experimental campaign (DTE2) at the Joint European Torus (JET). The study aimed to address three pivotal questions, each with implications for optimizing data accuracy, quality, and utility. The first question focused on determining the optimal short-gate settings for the MPRu. Extensive analysis revealed that conventional metrics, such as the Full Width at Half Maximum (FWHM) and spatial positioning of the proton island, were inadequate for precise short-gate configuration. It was concluded that the existing settings, characterized by a +30 offset from the signal onset, proved to be sufficient. This choice was driven by the necessity to distinguish between escape events, shadow events, and the proton island when plotting signals in a 2-D graph, proving effective across all detector channels. Accurate proton counting hinges on the precise assessment of protons within the escape event region, a task complicated by the interference of background events. This study investigated the point at which the accuracy of the escape event region diminishes by comparing the relative count with simulated data. Results demonstrated that higher-energy signals, positioned farther from the background-concentrated origin, yielded more accurate counts. Additionally, a correction factor based on simulated data is suggested for the unaccounted proton signals. The third question explored was the feasibility of modelling the proton island's location based on proton energy and the characteristics of the phoswhich scintillator detector. While initially promising, the model showed of limited use. The biggest limiting factor was the inconsistencies that originate in the detector themselves. It is not possible to account for the unique characteristics of each single detector, using the methods developed here. This could be changed if the individual characteristics of the detectors are taken into account in a future analysis.