Conversion coefficients for superheavy elements

Abstract

In this paper we report on internal conversion coefficients for Z = 111 to Z = 126 superheavy elements obtained from relativistic Dirac-Fock (DF) calculations. The effect of the atomic vacancy created during the conversion process has been taken into account using the so called "Frozen Orbital" approximation. The selection of this atomic model is supported by our recent comparison of experimental and theoretical conversion coefficients across a wide range of nuclei. The atomic masses, valence shell electron configurations, and theoretical atomic binding energies required for the calculations were adopted from a critical evaluation of the published data. The new conversion coefficient data tables presented here cover all atomic shells, transition energies from 1 keV up to 6000 keV, and multipole orders of 1 to 5. A similar approach was used in our previous calculations [1] for Z = 5 − 110.

Selected spectroscopic results on element 115 decay chains

“…either by emitting γ rays or by internal conversion. The latter is generally much more likely for low-energy transitions in superheavy nuclei [30]. Since the time difference between α decay and subsequent electromagnetic decay is usually confined to a few hundred nanoseconds (denoted as 'prompt coincidence'), neither the DSSSD itself nor its conventional read-out electronics is able to distinguish between signals from α-particle or conversion electron interactions in a given pixel of the DSSSD.…”

Atomic Radiations in the Decay of Medical Radioisotopes: A Physics Perspective

“…However, the transition energies from EADL have been replaced with values deduced from binding energies calculated at each propagation step using the RAINE Dirac-Fock code [42]. The RAINE code tends to slightly overestimate the binding energies of the inner shells and this results in some of the K Auger lines appearing above their experimental values [57, 58]. Transitions with negative energies, that is, energetically not allowed, were excluded.…”

Superheavy Element Studies with TASCA at GSI: Spectroscopy of Element 115 Decay Chains

“…One is tempted to interpret this spectrum as two γ-ray transitions of 194 and 237 keV and two Compton scattered events. Because of inner conversion arguments [34], both γ rays should have electic dipole, E1, character. Since the difference 237-194=43 is indicative for an excited rotational level with the same intrinsic structure, the level scheme displayed in Fig.…”