Eg. Drukarev, DISTRIBUTION OF ELECTRONS OVER FINAL-STATES IN BETA-DECAY OF ATOMIC TRITIUM BEYOND THE SHAKEOFF APPROXIMATION, Physical review. C. Nuclear physics, 54(6), 1996, pp. 3277-3278
Distribution between final states of the ion He+ in beta decay of atom
ic tritium is obtained. The final state interactions between beta-ray
and atomic shell are accounted for in the lowest order of expansion in
powers of the Sommerfeld parameter.