Grants and Contributions:

Grant or Award spanning more than one fiscal year. (2017-2018 to 2019-2020)

The matter-antimatter asymmetry in the universe is one of the biggest questions in fundamental physics, as well as philosophy. The neutron electric dipole moment (nEDM) is related to this asymmetry and can thus help shed light on this unsolved puzzle. Experiments searching for the nEDM have also ruled out several particle physics theories over the last five decades. So far, the most stringent limits on the nEDM have been set by experiments using ultracold neutrons; these are so slow that they are reflected by certain wall materials and can subsequently be stored and observed for hundreds of seconds.
TRIUMF’s Ultracold Neutron program aims at providing the world’s highest intensity of ultracold neutrons (UCN) to experiments. Furthermore, the Canadian-Japanese collaboration behind the TRIUMF UCN project wants to achieve a world leading ultimate sensitivity of 10−27 ecm to the nEDM. This search constitutes the flagship experiment of UCN physics.

The research program suggested in this proposal extends over two years and is intended as bridging grant for a new collaboration member. The rest of the UCN collaboration is supported by NSERC grant SAPPJ-2016-00024. The co-applicant is the principal applicant of this existing grant and is signing this application for administrative purposes only.
The main goal of this research proposal is the successful integration of the nEDM apparatus into the TRIUMF UCN facility. Two milestones are (i) filling and storing UCN into the existing Phase 1 nEDM apparatus, and (ii) the observation of Larmor precession of the stored UCN. This is very challenging due to the harsh environmental conditions in the direct proximity of the cyclotron accelerator which include (among others) high magnetic background fields, as well as time varying magnetic fields caused by other close-by experiments and infrastructure such as cranes and loading doors. The stability and homogeneity of the magnetic field, however, are crucial ingredients to the feasibility of Larmor precession experiments, and subsequently to the sensitivity of an nEDM measurement.
The applicant has gathered ample expertise in magnetic field observation and manipulation, as well as with nEDM measurements during her PhD studies and additionally is very experienced with UCN experiments by participating in UCN measurement campaigns at the institutes FRM-II in Germany, ILL in France, and PSI in Switzerland through her entire scientific career. This will be essential to the success of the UCN source and EDM experiment at TRIUMF.