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Oct 15 – 20, 2017
Harrison Hot Springs
Canada/Pacific timezone

Magnetic Field Apparatus for the Oak Ridge nEDM Experiment

Oct 17, 2017, 7:50 PM
Harrison Hot Springs

Harrison Hot Springs

100 Esplanade Avenue, Harrison Hot Springs, BC Canada V0M 1K0
Oral Magnetic field control (passive and active shielding, coil design, current sources) TuEv


Dr Simon Slutsky (Caltech)


A search for the neutron electric dipole moment (nEDM) will take place at the Spallation Neutron Source at Oak Ridge National Lab, aiming for a sensitivity of <$3\times10^{-28}$ e-cm. Polarized ultracold neutrons will precess in a 30 mG magnetic holding field inside a liquid helium cell, which will be doped with a minute amount of polarized He-3 to measure the precession frequency. Magnetic field gradients in the detector must be reduced below 3 ppm/cm relative to the holding field in order to mitigate the false nEDM signal due to the geometric phase effect and to increase the neutron and He-3 polarization lifetime. Material selection is restricted by the dual requirements of cryogenic and non-magnetic operation. I will discuss a 1/3-scale prototype magnet system that has demonstrated the required sensitivity using a nearly-hermetic, superconducting lead shield, as well as ongoing efforts to build and magnetically survey the full-scale cryostat and magnetic apparatus.

Funding Agency

US National Science Foundation, Grant 1506459


Primary author

Dr Simon Slutsky (Caltech)


Mr Alex Brinson (Caltech) Dr Bradley Filippone (Caltech) Mr Charles Osthelder (Caltech) Dr Christopher Swank (Caltech) Mr Daniel Molina (Caltech) Mr Robert Carr (Caltech) Dr Wanchun Wei (Caltech)

Presentation materials