Hannover 2003 – wissenschaftliches Programm
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A: Atomphysik
A 17: Postersitzung 2
A 17.29: Poster
Donnerstag, 27. März 2003, 16:00–18:30, Poster
Dielectronic recombination research of He-like heavy ions at the Heidelberg EBIT — •A. J. González Martínez1, J.R. Crespo López-Urrutia1, P. Guo1,2, V. Mironov1, U.I. Safronova3, H. Tawara1, X. Zhang1,2, and J. Ullrich1 — 1Max-Planck-Institut für Kernphysik, Saupfercheckweg, 1 69117 Heidelberg — 2Applied Ion Beam Physics Lab., Fudan University, Shanghai 200433 P.R. China — 3Department of Physics, University of Notre Dame, Notre Dame, IN, USA.
The electron beam ion trap (EBIT) is a convenient device to study electronic photorecombination into deep lying shells of highly charged ions. The dielectronic recombination (DR) process can be investigated through observing x-ray photons emitted via radiative stabilization of doubly excited levels. The present experiment with He-like Kr+34 was performed at the Heidelberg EBIT. The electron energy is ramped over an energy range from 5 to 14 keV. To determine excitation energies the resonance peaks have been fitted to multi-gaussian function. DR resonances due to He-like krypton ions are seen at low electron energies. The resonance excitation energy has been determined with an absolute accuracy of 220 ppm. To eliminate the energy shift caused by the space charge of dense electron beam, these peak positions are measured under different electron beam currents and extrapolated to the zero current. Also fits of x-ray peaks using different function profiles have been made to obtain photon energies with accuracy better than 15 eV. DR measurements at higher electron energy and the heavier elements are underway to investigate QED and nuclear sizes contributions.