Research on the performance of a diamond detector for the cross-section measurements at CSNS Back-n

The measurement of cross-section holds great significance in the field of nuclear physics. The Back-n white neutron facility located within the China Spallation Neutron Source (CSNS) has emerged as a significant contributor to this effort, offering high brightness and stable neutrons with a wide energy range (10°–108 eV). In the harsh environment of Back-n, diamond detectors have emerged as a promising option due to their high radiation hardness and compact size. A bi-parameter experiment (neutron time of flight and deposited energy) utilizing a single-crystal diamond was carried out at Back-n. The obtained time structure of the proton beam at CSNS aligns with previously reported results, thereby validating the approach. Additionally, the bi-parametric contour plot facilitated the identification of event bands corresponding to 12C(n,α0)9Be, 12C(n,n’)3α and 6Li(n,α)3H reactions. A simulation study using MATLAB analyzed the energy deposition distribution of 3–11 MeV neutrons in diamond detectors, which agreed with the identified event bands for the 12C(n,α0)9Be and 12C(n,n’)3α reactions. The peak positions of reaction channels within distinct neutron energy ranges demonstrated a remarkable concordance, with most below 2. This is the first time a diamond detector has been tested at Back-n. The results of the experiment have significant implications for the development of nuclear data measurement using diamond detectors at Back-n.