ENERGY-RESOLVED AND ANGLE-RESOLVED DOUBLE PHOTOIONIZATION IN ARGON LEADING TO THE 3P(-2)(1)D(E) FINAL IONIC STATE

Triple differential cross sections (TDCS) of argon double photoionizat ion to the Ar2+ (3p-2 1De) final ionic state have been measured at sel ected photon energies by means of energy- and angle-resolved electron- electron coincidences. The situation of resonance affected double ioni zation, i.e. direct double photoionization interfering with the popula tion of satellite states which autoionize to the same final state, man ifests itself strongly in the shape of the experimental TDCS patterns. At photon energies where the influence of the indirect channel is wea k, the experimental data are qualitatively compared with theoretical p redictions based on the individual contributing electron-pair wavefunc tions as given by the extended Wannier theory.