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We have measured the K-shell internal conversion coefficient, αK , for the 88.2-keV M 4 transition from the 106-day isomer to the ground state in 127 Te to be 484(6). When compared with Dirac-Fock calculations of αK , this result agrees well with the version of the theory that incorporates the effect of the K-shell atomic vacancy and disagrees with the one that does not. As a byproduct of this measurement, we have determined the beta branching from the isomer to be 2.14(3)%.

We find that the proton separation energy, S(p), of 73 Rb is −640(40) keV, deduced from the observation of β-delayed ground-state protons following the decay of 73 Sr. This lower-limit determination of the proton separation energy of 73 Rb coupled with previous upper limits from nonobservation, provides a full constraint on the mass excess with M( 73 Rb) =−46.01 ± 0.04 MeV. With this new mass excess and the excitation energy of the J π = 5/2 − isobaric-analog state (T = 3/2) in 73 Rb, an improved constraint can be put on the mass excess of 73 Sr using the isobaric-multiplet mass equation (IMME), and we find M( 73 Sr) =−31.98 ± 0.37 MeV. These new data were then used to study the composition of ashes on accreting neutron stars following Type I xray bursts. Counterintuitively, we find that there should be an enhanced fraction of A > 102 nuclei with more negative proton separation energies at the 72 Kr rp-process waiting point. Larger impurities of heavier nuclei in the ashes of accreting neutron stars will impact the cooling models for such astrophysical scenarios.

In this paper we report the first observation of x-ray radiation from the new Clemson University Electron Beam Ion Trap (CUEBIT). The analysis of the emitted dielectronic recombination x-ray photons from highly charged argon ions allowed us to probe parameters specific to the ion cloud inside the machine. Argon dielectronic resonances could provide a standard method to cross-compare the electron beam and ion cloud characteristics of different devices.

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