Spectral distribution of the two-photon decay of He-like krypton

We report Progress on a measurement of the spectral distribution of photons from the two-photon decay of the 2{sup 1}S{sub 0} level in heliumlike krypton. A measurement of the exact shape of the continuum singles spectrum of the two-photon decay in heliumlike ions provides a sensitive probe of the calculation of the transition probability. In our experiment a beam of Kr{sup 34+} ions is excited using a thin carbon foil and the subsequent decays are observed in an array of four x-ray detectors.