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 T ₀ chopper, we found that the curved guide can show comparable performance with the straight guide in the whole energy range of CNDCS when L ₁ ≥ 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 T ₀ chopper in the straight guide.

Keywords:

• Neutron transport
• Spallation neutron source
• Chopper spectrometer
• J-PARC

Acknowledgements

The authors thank S. Torii, S. Harjo and K. Shibata for valuable discussions.

Notes

Present address: Materials and Life Science Division, J-PARC Centre, Tokai, Ibaraki 319-1195, Japan.

Additional information

Notes on contributors

R. Kajimoto

1 Present address: Materials and Life Science Division, J-PARC Centre, Tokai, Ibaraki 319-1195, Japan.