Proton recoil telescope based on diamond detectors for measurement of fusion neutrons

TL;DR

This paper presents a diamond-based proton recoil telescope for measuring 14 MeV fusion neutrons, highlighting its radiation hardness, low gamma sensitivity, and promising initial testing results.

Contribution

It introduces a novel diamond detector configuration for neutron detection in fusion environments, demonstrating its potential advantages over traditional detectors.

Findings

Preliminary prototype shows promising efficiency.

Energy resolution is suitable for fusion neutron measurements.

Detector effectively suppresses background signals.

Abstract

Diamonds are very promising candidates for the neutron diagnostics in harsh environments such as fusion reactor. In the first place this is because of their radiation hardness, exceeding that of Silicon by an order of magnitude. Also, in comparison to the standard on-line neutron diagnostics (fission chambers, silicon based detectors, scintillators), diamonds are less sensitive to $\gamma$ rays, which represent a huge background in fusion devices. Finally, their low leakage current at high temperature suppresses the detector intrinsic noise. In this talk a CVD diamond based detector has been proposed for the measurement of the 14 MeV neutrons from D-T fusion reaction. The detector was arranged in a proton recoil telescope configuration, featuring a plastic converter in front of the sensitive volume in order to induce the (n,p) reaction. The segmentation of the sensitive volume, achieved by using two crystals, allowed to perform measurements in coincidence, which suppressed the neutron elastic scattering background. A preliminary prototype was assembled and tested at FNG (Frascati Neutron Generator, ENEA), showing promising results regarding efficiency and energy resolution.