Development of the Measurement System for the Search of an Electric Dipole Moment of the Electron with Laser-Cooled Francium Atoms

¹ Cyclotron and Radioisotope Center, Tohoku University, Miyagi, Japan
² Graduate School of Arts and Sciences, University of Tokyo, Tokyo, Japan
³ Department of Physics, Tokyo Metropolitan University, Tokyo, Japan
⁴ Department of Applied Physics, Tokyo University of Agriculture and Technology, Tokyo, Japan
⁵ Research Center for Nuclear Physics, Osaka University, Osaka, Japan
⁶ Advanced Science Research Center, Japan Atomic Energy Agency, Ibaraki, Japan
⁷ Department of Physics, Kyoto University, Kyoto, Japan
⁸ Department of Physics, Tohoku University, Miyagi, Japan
⁹ Department of Physics, Kyushu University, Fukuoka, Japan

^a e-mail: inoue_t@cyric.tohoku.ac.jp
^b Present address: Progress Technologies Inc.
^c Present address: Department of Physics, Indian Institute of Technology Roorkee, Uttarakhand, India
^d Present address: Department of Physics, Tokyo Institute of Technology, Tokyo, Japan

Published online: 20 March 2014

Abstract

We plan to measure the permanent electric dipole moment (EDM) of the electron, which has the sensitivity to the CP violation in theories beyond the standard model by using the laser-cooled francium (Fr) atom. This paper reports the present status of the EDM measurement system. A high voltage application system was constructed in order to produce the strong electric field (100 kV/cm) needed for the experiment. After conditioning, the leakage current was 10 pA when a high voltage of 43 kV was applied. Also, a drift of an environmental field was measured at the planned location of the Fr-EDM experiment. The drift is suppressed at present down to the level of 10 pT by installing a 4-layermagnetic shield. Improvements are still needed to reach the required field stability of 1 fT.