Nonsequential multiple ionization in intense laser pulses: Interpretation of Nen+ ion momentum distributions within a classical ?rescattering model?
Vector momentum distributions of Nen+ (n=1,2,3) ions created by 30 fs, 1 PW/cm2 laser pulses at
795 nm have been measured using recoil-ion momentum spectroscopy. In contrast to the distributions
for singly charged ions, peaking at zero momentum, distinct maxima along the light polarization axis
are observed for the multiply charged ions at 4 a.u. (Ne2+) and 7.5 a.u. (Ne3+), respectively.
Hence, mechanisms based on an instantaneous release of two (or more) electrons can be ruled out as a
dominant contribution to nonsequential strong-field multiple ionization. The positions of the maxima
are in accord with kinematical constraints set by the classical ?rescattering
model?.