High-resolution study of dielectronic capture by channeled Ti ions

Charge-changing processes have been investigated for 267--320-MeV Ti¹⁹⁺ and Ti²⁰⁺ ions channeled in a thin gold crystal. High-resolution measurements of the energy losses suffered by the charge-changed ions show that electron capture by the well-channeled particles is significantly enhanced when the projectile velocity corresponds to ejected KLL Auger-electron energies from doubly excited states in the rest frame of the ion. The measurements of dielectronic capture exhibit exceedingly narrow resonance widths and reveal a shift of the resonances toward higher energies.