Abstract
The Livermore electron-beam ion trap has been used to measure cross sections for electron-impact ionization of lithiumlike Ti, V, Cr, Mn, and Fe. The measurements were made using two variations of an x-ray technique that correlates ionization events with dielectronic-recombination photons. The cross sections were determined at one energy corresponding to approximately 2.3 times threshold. Ionization cross sections are measured (i) relative to the theoretical cross section for radiative recombination onto the n=2 shell for lithiumlike ions and (ii) relative to the theoretical cross section for direct excitation of the lithiumlike line q [1s2sS)2p →12s ]. The uncertainties in the ionization cross sections are estimated to be about 10% from the experiment together with a systematic uncertainty from the choice of normalization, which is 3% for radiative recombination and 10% for direct excitation. Good agreement is found with relativistic distorted-wave calculations.
- Received 22 February 1993
DOI:https://doi.org/10.1103/PhysRevA.48.2850
©1993 American Physical Society