THE DECAY MODES OF PROTON DRIP-LINE NUCLEI WITH A BETWEEN 42 AND 47

Neutron-deficient isotopes with Z = 21 to 26 have been produced as projectile-like fragments of an intense Ni-58 GANIL beam of 69 MeV/nucleon. The nuclei selected by the upgraded LISE3 spectrometer were identified and implanted in a silicon detector telescope. The 43Cr, 47Fe and 46Fe isotopes were identified for the first time whereas 45Fe, 45Mn, 44Mn and 42V were not observed, indicating probable instability of these nuclei against particle emission. Measurements of the half-lives of 43Cr and 46Mn have been performed and the analysis of their measured beta-delayed proton spectra has given, through the isobaric multiplet mass equation, an empirical estimation of their masses. Half-lives of 44Cr, 43V, 47Fe and 46Fe have also been measured. A discussion of various mass predictions for nuclei at the proton drip-line is given.