Measurements of triple differential cross section for double ionization
   in atomic calicum.
   A. De Fanis, K.J. Ross, H.-J. Beyer and J.B. West
   Department of Physics, Southampton University, Southampton, UK
   The triple differential cross section for 4s double photoionization in
   atomic calcium has been measured in the region of the giant 3p-3d resonance.
   Electrons are detected in coincidence in the plane perpendicular to the photon
   beam. Results are compared with previous ab-initio calculation and with
   similar results with the He atoms.