TIME-REVERSED INTERNAL-SOURCE HOLOGRAPHY

We have derived an expression for incident-beam-induced fine structure s at a local site. We show that using time-reversal arguments, local i ncident-beam-induced fine structures are equivalent to photoelectron h olography with an isotropic reference wave. We suggest that positron-b eam-induced desorption or Auger fine structures offer attractive alter natives to using electron beams because the positron-atom scattering f actor contains less angular anisortropy and the multiple scattering is weaker.