R. Moshammer et al., Three-body Coulomb problem probed by mapping the Bethe surface in ionizingion-atom collisions - art. no. 223201, PHYS REV L, 8722(22), 2001, pp. 3201
The three-body Coulomb problem has been explored in kinematically complete
experiments on single ionization of helium by 100 MeV/u C6+ and 3.6 MeV/u A
u53+ impact. Low-energy electron emission (E-e < 150 eV) as a function of t
he projectile deflection <theta>(p) (momentum transfer), i.e., the Bethe su
rface [15], has been mapped with Delta theta (p) +/- 25 nanoradian resoluti
on at extremely large perturbations (3.6 MeV/u Au53+) where single ionizati
on occurs at impact parameters of typically 10 times the He K-shell radius.
The experimental data are not in agreement with state-of-the-art continuum
distorted wave-eikonal initial state theory.