Helium (γ, 2e) triple differential cross sections at an excess energy of 60 eV

(γ, 2e) triple differential cross sections are presented for helium at 60 eV above the photodouble ionization threshold with energy-sharing ratios ( R = E 2 / E 1 ) for the two ejected electrons of R = 1, 5 and 11. The measurements were taken using a toroidal spectrometer and linearly polarized light from an undulator beamline (SU6) at the Super-ACO storage ring. Good agreement is found with TDCSs obtained by the CCC method and by the length gauge of 3C theory.