Evidence for KK-vacancy sharing in atomic collisions

New data are reported for the two-electron-one-photon Ksub(αα) decay mode of double K vacancies in both collision partners for a variety of asymmetric heavy-ion-atom systems. A model for KK-vacancy sharing is presented that predicts a double K-vacancy ratio Rsub(KK) = exp(-4Xsub(k) = Rsub(K)2 where Rsub(k) is the familiar single K-vacancy ratio. There is very good agreement between all available experimental results and the theoretical prediction, consistent with independent sharing of each vacancy in the 2psigma -2 configuration between the collision partners, through 2psigma-1ssigma radial coupling. (author)