Electron capture from oriented elliptic Rydberg atoms

Electron capture cross sections for coherent elliptic Rydberg states have been measured as a function of eccentricity. The ion impact velocity was parallel to the minor axis of the associated, classical elliptic orbit and both clockwise and anticlockwise orbital motion of the electron were studied. The incoming ions were 2.5 keV 23 Na + and the Rydberg target, with principal quantum number n=25, was formed by laser excitation of Li atoms with subsequent adiabatic switching of crossed, external electric and magnetic fields. A strong dependence on eccentricity and sense of orbital motion was found.