β-delayed proton radioactivity of 44Cr, 47Mn, 48,49Fe and 50Co

The proton-rich nuclei 44Cr, 47Mn, 48,49Fe and 50Co have been produced by fragmentation of a 58Ni beam at 650 MeV/u. The isotopic separation of these nuclei has been achieved with the GSI Projectile-Fragment Separator FRS. The isotopes have been identified in flight by ΔE-ToF-Bϱ measurements. After implantation in a stack of seven silicon detectors, the signals measured for implantation and radioactive decay were unambiguously correlated in time due to low counting rates. On the basis of the two proton peaks observed for 50Co at (2034±30) keV and (2740±41) keV with a half-life of (44±4) ms, a partial decay scheme is proposed for this nucleus. A single proton peak at (959±33) keV was observed for 48Fe with a half-life of (44±7) ms. This emission is attributed to the decay of the T = 2 isobaric analog state in 48Mn. No deviation from the quadratic form of the isobaric multiplet mass equation is observed. Additional information on β-delayed proton branches of 49Fe, 44Cr and 47Mn was also obtained.