ABSTRACT
The applications of resonance photoionization spectroscopy include the identification of high-lying atomic levels, the measurement of transition cross sections, and the identification of atomic species. The development of high-power tunable lasers has increased the popularity and range of application of many branches of spectroscopy. Perhaps the greatest expansion in effort has occurred in the field of resonance photoionization spectroscopy. Many of the applications exploit direct photoexcitation to the ionization continuum or to an autoionizing level above the ionization limit. An important application of resonance ionization spectroscopy is in the identification and assignment of high-lying atomic states in heavy elements such as the actinides and lanthanides. Before the invention of the laser, photoionization spectroscopy was only of limited application because it relied on the use of electrical discharge and arc lamps. The conventional light sources were of limited utility because of the short wavelengths and large spectral intensities required to induce atomic or molecular photoionization.
