Internal conversion coefficients for superheavy elements

Abstract

The internal conversion coefficients (ICC) were calculated for all atomic subshells of the elements with 104≤Z≤126, the E1...E4, M1...M4 multipolarities and the transition energies between 10 and 1000 keV. The atomic screening was treated in the relativistic Hartree-Fock-Slater model. The tables comprising almost 90000 subshell and total ICC were deposited at LANL preprint server [1].PACS: 23.20.Nx, 27.90.+b A. Introduction.-The γ-ray and conversion electron spectroscopies have contributed substantially to our knowledge of the nuclear decay schemes. The extensive tables of the theoretical internal conversion coefficients (ICC) have enabled the investigators to derive from the spectroscopic data the multipolarities and total intensities of the electromagnetic transitions depopulating the excited nuclear states. Existing tables of the ICC cover wide region of the atomic numbers: 30≤Z≤104 for all atomic shells [2] and 10≤Z≤104 for the K, L, and M shells [3].Very recently, Reiter et al [4] investigated the Z=102 isotope 254 No produced in a heavy ion reaction. By means of a multidetector γ-ray spectrometer, the authors identified the ground-state band of the even-even nucleus up to spin 14. The transitions of energy less than 100 keV could not be seen in the γ-ray spectrum since they proceed almost entirely via emission of the conversion electrons. In connection with a great effort to produce superheavy (SH) nuclei, e.g. the indication for formation of the Z=118, A=293 isotope [5], a further progress in the γ-ray and conversion electron spectroscopies can be expected. With this motivation, we calculated in this work the ICC for SH elements with Z up to 126.B. Calculations. -The internal conversion coefficients for the elements with Z ≥ 104 were evaluated using the program NICC [6]. The physical model used for the atom description was the Hartree-Fock one with the Slater's exchange term, the nucleus was *