2026-10-14T13:22:45Z https://www.scidb.cn/oai

10.57760/sciencedb.hjs.00711 2026-05-28T17:14:52Z

2026-05-28 Design and Simulation of the ∆E-E Silicon Telescope for the ⁶Li(n,t)⁴He Reaction at CSNS doi:10.57760/sciencedb.hjs.00711 en Abstract  [Background]: Thorium-based molten salt reactor (TMSR) utilizes FLiBe (LiF-BeF2) as the carrier salt for nuclear fuel. During the operation of a TMSR, a large amount of radioactive tritium is generated via the 6Li(n,t)4He reaction. Accurate assessment of tritium production in molten salt reactors requires precise cross-section data for this reaction. While the 6Li(n,t)4He reaction cross-section is considered standard in the neutron energy range from thermal neutron to 1 MeV, significant discrepancies exist in the high-energy region, particularly within the 4-7 MeV neutron energy range. [Purpose]: This study aims to design a physical scheme for a ΔE‑E silicon telescope array at the China Spallation Neutron Source (CSNS) platform based on the CSNS neutron spectrum, to enable accurate measurement of the 6Li(n,t)4He reaction cross‑section in the 4‑7 MeV neutron energy region. [Methods]: Using the Geant4 Monte Carlo code, the energy range of tritons produced by the 6Li(n,t)4He reaction for incident neutrons in the 4‑7 MeV range was simulated. The energy deposition behavior of tritons within this energy range in silicon was further simulated to determine the appropriate thicknesses of the ΔE and E detectors. After validating the reasonableness of a single ΔE‑E silicon telescope unit, a telescope array consisting of 10 detector units was designed, covering five backward angles (95°–155°) and five forward angles (25°–85°). Under the CSNS neutron energy spectrum, the counting distributions of tritons and other secondary particles from the 6Li(n,t)4He reaction on the ΔE‑E silicon telescope were simulated. The 6LiF target adopted a three‑layer structure (target–Al foil–target) with an Al foil thickness of 285 μm and a single LiF layer thickness of 5 μm, oriented at 65° relative to the neutron incident direction. [Results]: The simulation results determined the optimal detector thicknesses to be 40 μm for the ΔE detector and 300 μm for the E detector, ensuring that tritons penetrate the thin detector and stop in the thick one. The designed ΔE-E silicon telescope array enables efficient discrimination between tritons and other secondary particles generated by the 6Li(n,t)4He reaction within the 4-7 MeV neutron energy region under the CSNS spectrum. [Conclusions]: This work provides a theoretical basis for subsequent experimental designs aimed at measuring the 6Li(n,t)4He reaction cross-section at the CSNS platform. Monte Carlo simulation; Silicon Detector; ΔE-E particle identification li zheng Yu Chenggang Huang Bosong Su Xuedou Chen Jingen Cai Xiangzhou Ma Chunwang PUBLIC https://creativecommons.org/licenses/by/4.0/ dataset Science Data Bank