BETA-DECAY TO THE PROTON HALO STATE IN F-17

In the first experiment at the newly constructed ISOLDE Facility the f irst-forbidden beta-decay of Ne-17 into the first excited state of F-1 7 has been measured. It is a factor two faster than the corresponding mirror decay and thus gives one of the largest recorded asymmetries fo r beta decays feeding bound final states. Shell-model calculations can only reproduce the asymmetry if the halo structure of the F-17 state is taken into account.