Chapter 33 - Isotope Ratio Analysis Techniques using Photoionization as a Source of Ions

Abstract

This chapter describe the techniques and the important niches filled with respect to the study of stable isotope ratios of the lighter elements using photoionization as a source of ions. The laser resonance and non-resonance multi-photon ionization and the mechanisms for removing atoms from samples to give versatile and powerful methods for isotopic analysis are also elaborated. Techniques using photons to measure stable isotope ratios are many and varied although not of widespread use. The techniques described fill many valuable niche areas which are growing in size and application. Of particular importance is the capability for measuring isotope ratios in ever decreasing sample sizes with exceedingly high spatial resolution and is one area in particular which is expected to grow. The principal applications of these techniques are usually aimed at the analysis of rare or radioactive isotopes, particularly of heavy elements. One of the main problems in measuring isotope ratios using resonance ionization is the so-called odd-even effect.