Rapid adiabatic passage in laser cooling of fast stored ion beams

We present a simple and efficient method for the broadband laser excitation of ions in a fast beam by optical rapid adiabatic passage. The method relies on the frequency chirp affecting the ions in continuous-wave fixed-frequency laser light as a result of the Doppler effect when they are accelerated in local electrostatic fields. We have studied this excitation scheme at the Heidelberg Test Storage Ring and demonstrated its particular application to overcome collisional losses in laser cooling of fast stored ion beams.