Physical Review A
Stark deceleration and trapping of hydrogen Rydberg atoms
E. Vliegen, S. D. Hogan, Hansjürg Schmutz, Frédéric Merkt
Abstract
Hydrogen atoms in supersonic expansions with velocities in the range from $700\phantom{\rule{0.3em}{0ex}}\text{to}\phantom{\rule{0.3em}{0ex}}800\phantom{\rule{0.3em}{0ex}}\mathrm{m}∕\mathrm{s}$ have been excited to Rydberg-Stark states with principal quantum number $n$ between 20 and 40, decelerated to zero velocity in the lab frame using time-dependent inhomogeneous electric fields, and trapped in a two-dimensional electrostatic trap with an initial density of $\ensuremath{\approx}5\ifmmode\times\else\texttimes\fi{}{10}^{6}\phantom{\rule{0.3em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}3}$. The motion of the atomic cloud in the trap was observed by measuring the times of flight and images of the ${\mathrm{H}}^{+}$ ions produced by pulsed field ionization. The velocity distribution of the trapped atoms can be described by an effective temperature of $350\phantom{\rule{0.3em}{0ex}}\mathrm{mK}$. The decay of the population of trapped atoms does not follow a single-exponential behavior and has contributions from radiative and collisional processes.