Hamburg 2009 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

MS: Fachverband Massenspektrometrie

MS 1: Präzisionsmassenspektrometrie, Ionenfallen, FT-IZR-MS, Moleküle, Cluster I

MS 1.4: Talk

Monday, March 2, 2009, 12:00–12:15, VMP 8 R05

Systematic studies at ISOLTRAP using the invariance theorem — •Christine Boehm¹, Klaus Blaum², Ch. Borgmann², M. Breitenfeldt³, A. Herlert⁴, M. Kowalska⁴, D. Lunney⁵, S. Naimi⁵, Dennis Neidherr¹, M. Rosenbusch³, and Lutz Schweikhard³ — ¹Johannes Gutenberg University, Mainz, Germany — ²MPI for Nuclear Physics, Heidelberg, Germany — ³Ernst-Moritz-Arndt University, Greifswald, Germany — ⁴CERN, Geneva, Switzerland — ⁵University Paris-Sud 11, Orsay, France

ISOLTRAP is a Penning-trap mass spectrometer at the ISOLDE facility (CERN) where high-precision mass measurements on exotic nuclides are performed by determining their cyclotron frequency relative to that of a reference ion. For the obtained frequency ratios the present relative systematic uncertainty limit is δ m/m = 8·10⁻⁹ based on systematic studies using carbon cluster ions [1]. To further investigate the origin of the systematic uncertainty, and hopefully to decrease the magnitude, the invariance theorem by Brown and Gabrielse [2] was used. All three motional ion eigenfrequencies, as well as the conversion frequency were measured and compared. The difference Δ ω_c between the conversion frequency and the cyclotron frequency calculated from the invariance theorem was found to be mass independent and about 240 mHz. The knowledge of Δ ω_c in turn allows to estimate trap imperfections. The results of this study will be presented. [1] A. Kellerbauer et al., Eur. J. Phys. D 22, 53 (2003) [2] L. S. Brown, G. Gabrielse, Phys. Rev. A 25, 2423 (1982)