The two-photon decay in helium-like gold

Progress on a measurement of the spectral distribution of the two-photon decay of the 2¹S₀ level in helium-like gold is reported. A measurement of the exact shape of the continuous spectrum of the two-photon decay in heavy helium-like ions provides a sensitive test on the details of the complete structure of a helium-like system. In our experiment at GSI, a beam of 106.6 MeV/u Au⁷⁷⁺ ions is excited by a thin Aluminum foil and the subsequent decays are observed in an array of Ge(i) detectors. This revised version was published online in July 2006 with corrections to the Cover Date.