  Results of decay spectroscopy on nuclei in vicinity of the doubly magic 48Ni
are presented. The measurements were performed with a Time Projection Chamber
with optical readout which records tracks of ions and protons in the gaseous
volume. Six decays of 48Ni including four events of two-proton ground-state
radioactivity were recorded. An advanced reconstruction procedure yielded the
2p decay energy for 48Ni of Q2p = 1.29(4) MeV. In addition, the energy spectra
of \b{eta}-delayed protons emitted in the decays of 44Cr and 46Fe, as well as
half-lives and branching ratios were determined. The results were found to be
consistent with the previous measurements made with Si detectors. A new proton
line in the decay of 44Cr corresponding to the decay energy of 760 keV is
reported. The first evidence for the \b{eta}2p decay of 46 Fe, based on one
clear event, is shown.
