Direct and β-delayed multi-proton emission from atomic nuclei with a time projection chamber: the cases of 43Cr, 45Fe, and 51Ni

The two-proton radioactivity of 45Fe was studied experimentally with a time projection chamber. The aim of the experiment was the reconstruction of the proton tracks in three dimensions. Energy and angular correlations have been determined and the data are compared with theoretical models, in particular with a three-body model. Moreover, the decay of 43Cr was studied and β-delayed one-, two- and three-proton emission could be established. The correlations observed for β-delayed two-proton emission favour a sequential emission. Finally, β-delayed two-proton emission was observed for the first time for 51Ni.