Progress Toward a Cold Atom Fountain Electron Electric Dipole Moment Experiment

Harvey Gould, Jason Amini

Edward A. Hinds

Jason Amini, Harvey Gould

Harvey Gould

Michael R. Tarbutt, B. E. Sauer, J. J. Hudson +1 more

We propose an experiment to measure the electric dipole moment (EDM) of the electron using ultracold YbF molecules. The molecules are produced as a thermal beam by a cryogenic buffer gas source, and brought to rest in an optical molasses that cools them to the Doppler limit or below. The molecular cloud is then thrown upward to form a fountain in which the EDM of the electron is measured. A non-zero result would be unambiguous proof of new elementary particle interactions, beyond the standard model.

Fang Fang

In this thesis, the basic principles of the C, P, T symmetries are introduced and the experiments to measure the electric dipole moment (EDM) are summarized. We propose an experiment to search for the electric dipole moment of the electron using Cs and Rb atoms in 1D optical lattice traps. Our projected sensitivity is 3iN10-30 e-cm with an integration time of 12 hours, which is a 500-fold improvement over the current limit. The potential sources of noise and systematic errors in our designed experiment are analyzed. The preliminary test results for charging small ITO coated electric field plates are given, and the designs of a magnetic shielding system and cancellation coils are also described. We trapped the Cs and Rb atoms in the MOT, and launched Cs atoms up 90 cm from the MOT to the center of the measurement chamber while guided by a resonator enhanced 1D optical lattice trap with transport efficiency up to 50%. The 1064 nm wavelength optical lattice is made in a 2 m long build-up cavity of light, and provides a transverse guide depth of up to 250 ƒÝK. Before they reach the top of their trajectory, the atoms are stopped and cooled by optical molasses, becoming trapped in the 1D lattice. We also demonstrate multiple launches of Cs atoms to the trap.