Influence of magnetic fields on recombination rates of Au25+

Recombination of Au25+-ions has been investigated in a single-pass merged-b eams experiment at the UNILAC of GSI in Darmstadt. Very low energies in the electron-ion center-of-mass frame were particularly addressed. At E-rel = 0 eV we found a recombination rate exceeding the expectations by a factor o f 365. For further investigation of this enhancement, the electron density and the magnetic field guiding the electron beam were varied. While an incr ease of the electron density by a factor of 10 had little influence, the me asured rate coefficient increased significantly with the magnetic field str ength.