LIFETIMES OF LEVELS IN F-20

Recent Coulomb shift calculations for the level structure of the Na-20 and F-20 nuclei predict that the 3(3)(+) state at 2.966 MeV in F-20 i s the mirror of the 2.646 MeV state in Na-20, which is of considerable importance for the reaction rate of Ne-19(p,gamma)Na-20. Shell model predictions suggest a lifetime of 3.5 fs for the state in F-20, in dis agreement with the experimentally determined value of 60+/-40 fs. The lifetime of low excited states in F-20 has therefore been remeasured u sing the Doppler shift attenuation method (DSAM) and an upper limit of less than or equal to 12 fs for the 2.966 MeV state has been obtained .