Institut für Kernphysik, Justus-Liebig-Universit?t, 35392 Giessen, Germany, DE Gesellschaft für Schwerionenforschung (GSI), 64291 Darmstadt, Germany, DE Institute for Nuclear Physics, 31-342 Kraków, Poland, PL
Abstract:
Recombination of fully stripped U92+ ions with electrons has been investigated at the Experimental Storage Ring (ESR) in Darmstadt. Absolute recombination rate
coefficients have been measured for relative energies from 0 to 33 eV. For energies greater than 20 meV the experimental result
is well described by the theory for radiative recombination (RR). Below 20 meV the experimental rate increasingly exceeds
the RR calculation as observed previously in the recombination of light bare ions as well as of Bi83+. This low-energy rate enhancement is shown to scale as Z2.6 for bare ions, where Z is the atomic number of the ion. The U92+ recombination rate enhancement is insensitive to changes of the electron density. Variation of the magnetic guiding field
strength from 80 mT to 120 mT resulted in oscillations of the recombination rate at 0 eV. The oscillations are partly attributed
to changes of the transverse electron temperature accompanying the change of the magnetic guiding field strength; partly they
may be caused by uncompensated small changes of the interaction angle between the two beams.
Received 1st March 2001 and Received in final form 20 April 2001