Improved isotope enrichment system for processing minute noble gas samples

The development of a plasma ion source/velocity filter mass spectrometer to provide isotopic enrichment of minute noble gas samples prior to resonance ionization spectroscopy is described. The analysis of noble gas samples for the extremely rare (∼ 10-12 abundance) 81Kr and 85Kr isotopes by resonance ionization spectroscopy has practical applications in fields as diverse as environmental research, climatology, and particle physics. The system performance, including identification of major interference sources (hydrides, fast neutrals, and scattering), and implementation of changes to overcome these, is discussed. (author)