A proposed method of efficient laser trapping of neutral radium atoms

Abstract

We report theoretical studies of an efficient accumulation of Ra-225 atoms in a magneto-optical trap (MOT) from an atomic beam. The number of atoms in the trap is limited due to the large leakage into metastable D states from the cooling transition and the loss mechanism from collisions with the background gases and with other elements in the atomic beam. We propose a setup consisting of an efficient Zeeman slower, an optical atomic beam deflector, and an Egg-MOT, which provides a large capture velocity, e.g. the Zeeman slower capture velocity of 581 ms(-1) and the MOT capture velocity of 46 ms(-1). Furthermore, the pure slow atomic beam produced by the optical atomic beam deflector can maximize the number of trapped atoms and their lifetime in a ultra high vacuum chamber by minimizing the collisional loss. Our proposed setup allows for the search for a permanent electric dipole moment based on laser-cooled and trapped radium atoms with improved sensitivity.