Author ORCID Identifier

Date Available


Year of Publication


Degree Name

Doctor of Philosophy (PhD)

Document Type

Doctoral Dissertation


Arts and Sciences


Physics and Astronomy

First Advisor

Dr. Chris Crawford


The n2EDM experiment is being construct at Paul Scherrer Institute to measure the electric dipole moment of the neutron (nEDM), in a search for new physics which could help explain the baryon asymmetry of the universe. To reach the experimental sensitivity goal of $d_n \sim 10^{-27}$, over an order of magnitude improvement from the current world limit, a spin polarization transfer efficiency of 99\% for ultracold neutrons entering or exiting the precession chamber is required, placing a stringent requirement on the adiabaticity of the magnetic field taper in the neutron guide system. The spin transport fields transition from 5~T (longitudinal) in the superconducting polarizer to 30~$\mu$T (vertical) at the entrance of the magnetic shield room, further tapering to 1~$\mu$T in the precession chambers. Utilizing the magnetic scalar potential, the design process was separated into two phases: determination of the ideal magnetic field profile, and calculation of surface current coils within the geometrical constraints of the apparatus to realize this field. New techniques were developed to model the magnetic field and optimize adiabaticity of the spin transport, and to design a coil to compensate for magnetic fringes on the inner wall of the shield. The resulting hand-wound spin transport coils were installed and tested at PSI, and exceeded the spin transport requirements.

Digital Object Identifier (DOI)

Included in

Nuclear Commons