Options for a very cold neutron source for the second target station at SNS

Abstract

Simulation work is underway to identify a very cold neutron source solution that would provide an order of magnitude higher neutron output than the conventional moderator suite. Moderator candidates such as water ice, beryllium, ortho-D2, CH4, and neon all solid at temperatures of 4-6 K were investigated. At present no moderator option was able to achieve the set goal; ortho-D2 and CH4 seem to be the most promising options.