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A: Fachverband Atomphysik

A 27: Posters: Electron scattering and recombination

A 27.5: Poster

Thursday, March 13, 2008, 16:30–18:30, Poster C3

Systematic effects on the absolute energy determination of dielectronic recombination resonances — •Christian Beilmann, José R. Crespo López-Urrutia, Volkhard Mäckel, Hiro Tawara, and Joachim Ullrich — Max-Planck-Institut für Kernphysik, Heidelberg, Germany

The dielectronic recombination (DR) is a resonant electron capture process by a highly charged ion, where the kinetic energy of the captured electron is transfered to a bound electron thus exciting it. By measuring DR, the electronic energy levels can be determined with high precision. The ions are produced and trapped in an electron beam ion trap (EBIT) using an intense electron beam. Varying the electron energy allows measuring the electron capture resonances. In these experiments the space charge potential of the electron beam (partially compensated by the ions) has to be inferred. In previous experiments it was observed that the trapping potential depth had an influence on the space charge potential as well as on its linearity with respect to the current of the electron beam. The precise determination of the space charge potential is an issue of ongoing experiments. The resonance energies of the DR at several trapping potentials are studied and compared with each other. Applying the corrections obtained in these investigations leads to an higher accuracy for the absolute resonance energies.