Neutron EDM Experiment with an Advanced Ultracold Neutron Source at TRIUMF

TL;DR

This paper reports progress on developing a high-intensity ultracold neutron source at TRIUMF for a neutron EDM experiment aiming at unprecedented sensitivity, including recent commissioning and system operation milestones.

Contribution

It presents the development and commissioning progress of a novel super-thermal UCN source and EDM spectrometer with enhanced capabilities for neutron EDM measurement.

Findings

First production of UCNs with the new source system

Operational status of the complete source system (excluding liquid deuterium moderator)

Progress in magnetic and handling components for the EDM spectrometer

Abstract

The TRIUMF Ultracold Advanced Neutron (TUCAN) collaboration has been developing a high-intensity ultracold neutron (UCN) source aimed at searching for the neutron electric dipole moment (EDM) with a sensitivity goal of $10^{-27}\ e{\rm cm}$. This article reports on recent progress in commissioning of the UCN source and in the development of the neutron EDM spectrometer. In its final configuration, the accelerator-driven super-thermal UCN source will enable a neutron EDM experiment with two orders of magnitude improved statistics compared to the current best experiment. Substantial progress in 2024 allowed the collaboration to operate the complete source system, with the exception of the liquid deuterium cold moderator, resulting in the first production of UCNs. The status of the EDM spectrometer is also presented, with emphasis on UCN handling components and magnetic subsystems relevant to field control, shielding, and magnetometry.