Journal of Physics Conference Series
Cooling effects in the Stark deceleration of Rydberg atoms/molecules with time-dependent electric fields
Yoshihiro Yamakita, R Takahashi, Koichi Ohno, Simon R. Procter, Glenn E. M. Maguire, T. P. Softley
Abstract
This paper presents calculations for realizing the deceleration of H 2 Rydberg molecules with n = 16, where n is the principal quantum number. A double-dipole decelerator (Softley T P, Procter S R, Yamakita Y, Maguire G and Merkt F 2005 J. Elec. Spectrosc. Relat. Phenom. 144–147 113) operated with an optimum time-dependent electric field allows, in principle, complete deceleration of the Rydberg molecules to zero mean velocity. A bunch of molecules in a supersonic beam is decelerated from the initial velocity centered at ∼900 ms −1 and translational temperature 1 K to the final velocity 0 ms −1 and temperature 13 mK. The calculations are performed using the 4th-order symplectic integrator based on representations in phase space { q, p }, and show that an ensemble with narrow δ q 0 and broad δ p 0 distribution is converted to one at standstill with broad δ q and narrow δ p . Cooling effects are reinforced by field ionization in which the fast components that move to regions of high electric field are effectively filtered out.