Improved energies for the 5.2 keV M1 and 42.0 keV M2 nuclear transitions in 83Rb

Abstract

The low-energy electron spectrum following the decay of 83Sr was analysed at high instrumental resolution by an electrostatic spectrometer. Significantly improved energies of \( 5235.7\pm 0.8\) and \( 42078.0\pm 1.8\) eV were determined from the conversion electron spectra for the nuclear transitions depopulating the first 3/2- and the second \( 9/2^{+}\) excited states in 83Rb to the \( 5/2^{-}\) ground state, respectively. The M1 character for the 5.2keV nuclear transition was confirmed and the E2 admixture parameter \( \delta^{2}(E2/M1)=(2.6\pm 0.2)\times 10^{-5}\) was obtained. Values of \( 2.8\pm 0.2\), \( 3.8\pm 0.2\), \( 1.4\pm 0.3\), \( 1.4\pm 0.4\), and \( 4.1\pm 0.3\) eV were determined for the K, L1, L2, L3, and M1 natural atomic level widths of rubidium, respectively.