DOUBLE RYDBERG STATES FORMED IN STABILIZED TRIPLE ELECTRON-CAPTURE

Double Rydberg states were populated by triple electron capture in col lisions of highly charged ions with atoms. The highest stabilization o f states produced by triple capture at upsilon congruent to 0.2 a.u. w as found for binding energies of the projectile electrons near the lim its of the (2,n,n') and (3,n,n') series. Population of triply excited double Rydberg states was confirmed by the emission of Rydberg transit ions. Results are interpreted by two successive autotransfer into Rydb erg states for (3,n,n') states and of one-step two-electron autotransf er for (2,n,n') states.