Voluminous D2 source for intense cold neutron beam production at the ESS

TL;DR

This paper explores the design and performance of a large-volume D2 moderator at ESS to enhance cold neutron beam production for fundamental physics experiments, complementing existing moderator concepts.

Contribution

It introduces a novel voluminous D2 moderator concept and assesses its neutronic performance for the first time at ESS.

Findings

The voluminous D2 moderator can significantly increase neutron flux.

Performance assessments show promising results for fundamental physics applications.

The design offers a complementary option to existing moderators.

Abstract

The development of the flat moderator concept at ESS recently opened up the possibility that a single flat moderator above the target could serve all the scattering instruments, that rely on high brightness. This would allow for the introduction of a fundamentally different moderator below the target for the complementary needs of certain fundamental physics experiments. To facilitate experiments depending on the total number of neutrons in a sizable beam, the option of a voluminous D2 moderator, in a large cross-section extraction guide is discussed and its neutronic performance is assessed.