title: Cooling by spontaneous decay of highly excited antihydrogen atoms in magnetic traps.
abstract: An efficient cooling mechanism of magnetically trapped, highly excited antihydrogen (H) atoms is presented. This cooling, in addition to the expected evaporative cooling, results in trapping of a large number of H atoms in the ground state. It is found that the final fraction of trapped atoms is insensitive to the initial distribution of H magnetic quantum numbers. Expressions are derived for the cooling efficiency, demonstrating that magnetic quadrupole (cusp) traps provide stronger cooling than higher order magnetic multipoles. The final temperature of H confined in a cusp trap is shown to depend as approximately 2.2T(n0)n(0)(-2/3) on the initial Rydberg level n0 and temperature T(n0).
authors.affiliation: ITAMP, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge Massachusetts 02138, USA.
authors.forename: T
authors.initials: T
authors.lastname: Pohl
authors.forename: H R
authors.initials: HR
authors.lastname: Sadeghpour
authors.forename: Y
authors.initials: Y
authors.lastname: Nagata
authors.forename: Y
authors.initials: Y
authors.lastname: Yamazaki