CryoEDM: a cryogenic experiment to measure the neutron Electric Dipole Moment
Journal of Physics: Conference Series 251:1 012055
Abstract:
We have constructed an instrument, CryoEDM, to measure the neutron electric dipole moment to a precision of 10−28 e cm at the Institut Laue-Langevin. The main characteristic is that it is operating entirely in a cryogenic environment, at temperatures of 0.7 K within superfluid helium. Ultracold neutrons are produced in a superthermal source and stored within the superfluid in a storage cell which is held in a magnetic and electric field. NMR measurements are carried out to look for any shifts in the neutron Larmor precession frequency associated with the electric field and the neutrons are detected in-situ in the superfluid. Low temperature SQUID magnetometry is used to monitor the magnetic field. We report on the current status of the project that is now being commissioned and give an outlook on the future exploitation of the instrument.Measuring the electric dipole moment of the neutron: The cryoEDM experiment
Proceedings of Science EPS-HEP 2009 376
Abstract:
The cryoEDM experiment at the Institut Laue-Langevin in Grenoble will measure the electric dipole moment (EDM) of the neutron with unparalleled precision. A neutron EDM arises due to CP violation. The cryoEDM experiment is sensitive to levels of CP violation predicted by many “beyond the standard model” theories and the result will therefore constrain or support these theories. The current limit to the neutron EDM stands at d_n<2.9x 10^-26 e cm as measured with a room temperature experiment. By operating in superfluid helium below 0.9 K and collecting high densities of ultra cold neutrons, the cryoEDM experiment will improve on the existing limit or measure an EDM. High precision magnetometry is essential to reduce the systematic errors in the cryoEDM experiment originating from changes in the magnetic environment. We present the cryoEDM apparatus and technologies.Tracking geomagnetic fluctuations to picotesla accuracy using two superconducting quantum interference device vector magnetometers
Review of Scientific Instruments AIP 84 024501