Time-Resolved Spectroscopy of Ions Using CW Laser Excitation

We review the field of lifetime measurements on ions using fast beams selectively excited by fixed frequency and tunable CW lasers. These experiments involve the sampling of fluorescent intensities as a function of the separation between the selective excitation region and the detection region. Three variations of the FIBLAS (Fast Ion Beam-Laser Spectroscopy) technique are described. Two of these methods are time-of-flight measurements employing either crossed or collinear beam geometries. The third method, which is new, also uses the collinear beam arrangement but avoids any mechanical motion of either the excitation or detection regions in contrast to the other FIBLAS methods. All three methods are capable of determining excited state lifetimes to 1% or better.