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MS: Massenspektrometrie

MS VIII: HV VIII

MS VIII.1: Hauptvortrag

Mittwoch, 5. April 2000, 14:30–15:00, HS VII

Radioactive beams with isobaric and isomeric purity — •Gerhard Huber — Institut fuer Physik Postfach 3980 55029 Mainz

Radioactive beams can be produced at mass separators on-line with high temperature targets at accelerators. With high energy reactions many nuclides are accessible, in several cases even far out to the limit of nuclear stability. In these unspecific reactions however the nuclides of interest are often blended by isobars and isomers, which cannot be suppressed by standard mass separation. Some elements can be selected by a special target ion source configuration ( cold line for noble gases or surface ionisation for alcalis ).Therefor the high optical selectivity of a multistep laser resonance ionisation is used at several on-line facilities. The laser ion source at ISOLDE/CERN can now be operated with an improved frequency control and with third harmonic generation for deep UV light needed for several elements. Recent experiments on Be ,Cu, Ag will be reported where the laser ion source yields high ionisation efficiency and isobaric selectivity as a result of the ion source construction and the laser system performance. The spin isomers in Ag could be selectively ionised by tuning accurately the laser to the different hyperfine components of the resonance line. The potential of a selective laser ionisation at on-line

separators will be discussed by comparing with recent developments in trace analysis and also its sensitivity for direct laser spectroscopy for heavy elements.