Decay of 48K, 49K and 50K

The 48K, 49K and 50K nuclides have been produced in high energy fragmentation and analyzed by mass spectroscopy techniques. Their half lives have been measured as 6+-1s, 1.1+-0.3s and 0.7+-0.3s, respectively. The γ-rays from their radioactive decay have been observed and the corresponding γ intensities measured. 50K is shown to be a delayed neutron emitter. The antianalog states in the daughter Ca nuclei with a (1d3/2)-1 neutron configuration, preferentially populated in the β decay, have been located. The corresponding 1d3/2 neutron single particle energy is found to remain approximately constant for these neutron rich Ca isotopes