Frankfurt 2006 – scientific programme

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MS: Massenspektrometrie

MS 6: Präzisions-MS kurzlebiger Nuklide 2

MS 6.2: Talk

Thursday, March 16, 2006, 11:10–11:25, H1

Extraction efficiency and the extraction times of the SHIPTRAP gas stopping cell — •Sergey Eliseev — GSI,Planckstrasse 1, 64291,Darmstadt

The SHIPTRAP stopping cell is a part of the SHIPTRAP mass spectrometer. Its good performance is critical for the overall efficiency of the spectrometer. For the investigation of the extraction efficiency and the extraction times of the SHIPTRAP stopping cell as well as for study of chemical processes taking place in the gas cell 219Rn recoil ions from the a-decay of a calibrated point-like 223Ra ion source were used. The extraction times were measured to be shorter than 10 ms at a helium gas pressure of 40 mbar. Thus, nuclides with half-lives as short as a few milliseconds are accessible for the various experiments planned at SHIPTRAP. Extraction efficiency of up to 30% at 50 mbar of helium gas pressure in the gas cell was obtained. The estimated total efficiency of the gas cell is about 10%, determined by the product of calculated stopping and measured extraction efficiency. Factors limiting the efficiency are quantitatively understood. Under proper conditions, ion-molecule reactions in the gas cell do not seem to limit the efficiency of the gas cell significantly.