ELECTRON CORRELATION IN 3-BODY COULOMB STATES OF BARIUM

We excited a special class of states of a three-body Coulomb system, p opulating double Rydberg states of the type Ngng [N=5-9, n much greate r than N where N (n) is the principal quantum number of the inner (out er) valence electron] in Ba with both valence electrons in non-core-pe netrating orbits with the same orbital angular momentum. Electron corr elation effects manifest themselves by the appearance of additional Nh n1 resonances, a rapid increase of the observed quantum defects with N , as well as a significant decrease of the autoionization rate for N=9 .