Charge-State Distributions after Beta Decay of 6He to Form 6Li+

The shake-off processes and charge-state fractions of Li-6(+), Li-6(++), and Li-6(3+) were studied following the beta decay of 6He in the 1s(21)S(0), 1s2s(1)S0, and (1)s2s(3)S(1) initial states. The sudden approximation was used, together with fully correlated Hylleraas wave functions and pseudostates. A projection operator method was introduced to separate the charge-state fractions in the positive energy region of overlapping continua. The results show that Li-6(++ )(single-ionisation) remains dominant, even in the energy range E>0, where the formation of Li-6(3+) (double-ionisation) is energetically allowed. The results reduce disagreements with the experiment for the fraction of Li-6(3+) by nearly an order of magnitude, but substantial disagreements remain that are inconsistent with the sudden approximation widely used in other similar work.