The TUCAN Neutron Electric Dipole Moment Experiment

Abstract

The goal of the TRIUMF Ultra-Cold Advanced Neutron (TUCAN) Collaboration is to successfully make a new measurement of the neutron electric dipole moment (nEDM) with an uncertainty of 1 × 10 −27 e-cm in 400 days of run time, a one order of magnitude improvement compared to the current world's best result. The experiment is unique in using a spallation-driven superfluid helium (He-II) source of ultracold neutrons (UCN). We are now at the stage of upgrading the UCN source to produce world-leading UCN densities, using a new He-II cryostat that has undergone cryogenic testing at KEK in 2020-21. We are also assembling the experimental components of the EDM experiment, including a magnetically shielded room, coils, and atomic magnetometers.