Curved neutron guide of the cold neutron disk-chopper spectrometer at J-PARC

Abstract

We have investigated the usefulness of a curved guide for the cold neutron disk-chopper spectrometer (CNDCS), which is under construction for the Japan Proton Accelerator Research Complex (J-PARC), by Monte Carlo simulation. By comparing with a model with a straight guide and a T₀ chopper, we found that the curved guide can show comparable performance with the straight guide in the whole energy range of CNDCS when L₁ ≥ 30 m. Interestingly, the curved guide surpasses the straight guide in neutron flux at E ≤ 20 meV, where CNDCS is optimized, because of the loss of flux at the gap for the T₀ chopper in the straight guide.