OPTOGALVANIC PHOTOIONIZATION SPECTROSCOPY

This paper presents, for the first time, a systematic study of an opto galvanic method for photoionization spectroscopy. The method is partic ularly attractive for refractory and complex atoms, such as lanthanide s and actinides. The relevant characteristics of the hollow cathode di scharges used for this study are discussed in detail, along with the e xperimental protocol for this spectroscopic method. The rapid optogalv anic effect, which results solely from photoionization, is also descri bed. Finally, we present as an example of the application of this meth od, a table containing some of the recorded uranium photoionization li nes in the 16300-20500 cm(-1) range, along with typical samples of the uranium single-colour photoionization spectrum recorded using the rap id optogalvanic technique. A brief discussion of the sensitivity of th e rapid optogalvanic effect is also presented. It appears that the rap id optogalvanic effect is very effective in the detection of highly ex cited levels. This technique permitted the observation of many new sin gle-colour resonant ionization uranium lines.