LOW-ENERGY TWO CENTER ELECTRONS FROM HEAVY-ION HELIUM COLLISIONS

W. Schmitt1, R. Moshammer1, H. Kollmus1, B. Bapat1, M. Schulz1,6, R. Mann2,
R. D=F6rner3, Th. Weber3,=20
A. Cassimi4, L. Adoui4, J.P. Grandin4, S. Hagmann5, F. O'Rourke7, R.E.
Olson6, J. Ullrich1

1Fakult=E4t f=FCr Physik, Universit=E4t Freiburg, 79104 Freiburg, Germany
2Gesellschaft f=FCr Schwerionenforschung (GSI), 64291 Darmstadt, Germany
3Institut f=FCr Kernphysik, Universit=E4t Frankfurt, 60486 Frankfurt,=
 Germany
4CIRIL, 14040 Caen, France
5JRM, Kansas State University, Manhattan, USA
6University of Missouri, Rolla, USA
7Queens University, Belfast, United Kingdom

Single ionization of helium has been studied with different projectiles
covering a wide range of perturbation strengths using the combined
recoil-ion electron momentum spectroscopy (Reaction-Microscopes). Within
these  experiments the complete many-particle final state in momentum space
has been mapped with high resolution. Special emphasis is given to the
emission of low energy electrons (Ee<100 eV), the dominant contribution to
the total cross section.=20