Fully differential (e,3e) cross sections for electron impact double
ionization of helium in the keV regime

A.S. Kheifets$^\star$, I. Bray$^\ast$, A. Lahmam-Bennani$^\dagger$,
A. Duguet$^\dagger$  and I. Taouil$^\dagger$,

$^\star$ RSPhysSE, Australian National University, Canberra
A.C.T. 0200,

$^\sharp$ESM Centre, Flinders University
of South Australia, GPO Box 2100, Adelaide S.A. 5001, Australia

$^\dagger$Laboratoire des Collisions Atomiques et Mol\'{e}culaires,
Bat. 351, Universit\'{e} de Paris-Sud
91405 Orsay Cedex, France

We determine, both experimentally and theoretically, the
fully-resolved cross-section of the double ionization of helium by
5.5~keV electron impact. Two electrons are ejected in the continuum
with energies $E_1$=$E_2$=4 and 10~eV. Calculations are performed
using the convergent close-coupling (CCC) method which treats the
interaction between the two slow ejected electrons to infinite
order. The interaction of the fast incident electron with the target
is described within the 1st Born approximation.