A Segmented Total Energy Detector (sTED) optimized for (n,) cross-section measurements at n_TOF EAR2

Alcayne, V.*; 木村 敦; 他134名*

Radiation Physics and Chemistry, 217, p.111525_1 - 111525_11, 2024/04

https://doi.org/10.1016/j.radphyschem.2024.111525

The neutron time-of-flight facility n_TOF at CERN is a spallation source dedicated to measurements of neutron induced reaction cross-sections of interest in nuclear technologies, astrophysics, and other applications. Since 2014, Experimental ARea 2 (EAR2) is operational and delivers a neutron fluence of neutrons per nominal proton pulse, which is 50 times higher than the one of the other experimental area. The high neutron flux at EAR2 results in high counting rates in the detectors that challenged the previously existing capture detection systems. For this reason, a Segmented Total Energy Detector (sTED) has been developed to overcome the limitations in the detector's response, by reducing the active volume and by using a photo-multiplier (PMT) optimized for high counting rates. This paper presents the main characteristics of the sTED, including energy and time resolution, response to -rays, and provides details for the Pulse Height Weighting Technique (PHWT). The sTED has been validated to perform neutron-capture cross-section measurements in EAR2 in the neutron energy range from thermal up to at least 400 keV.