Decay of Ce144 and Pr144

The beta and gamma spectra from the decay of ${\mathrm{Ce}}^{144}$ and ${\mathrm{Pr}}^{144}$ have been investigated by means of a magnetic-lens beta spectrometer and single-channel scintillation spectrometers. Three partial beta spectra with end-point energies and relative intensities of 184 kev (30%), 245 kev (5%), and 320 kev (65%) were observed for ${\mathrm{Ce}}^{144}$. Gamma rays and internal conversion lines corresponding to 54, 80, and 134-kev transitions were also detected. Internal conversion coefficients indicate an $M1$ multipolarity for the 80- and 134-kev transitions. ${\mathrm{Pr}}^{144}$ yields three partial beta spectra with end-point energies and relative intensities of 0.90 Mev (2%), 2.45 Mev (3%), and 3.15 Mev (95%). Corresponding gamma rays were also detected. Beta-gamma and gamma-gamma coincidence measurements substantiate the proposed decay scheme.