Search results for "LAWRENCIUM"
showing 4 items of 14 documents
Direct Mapping of Nuclear Shell Effects in the Heaviest Elements
2014
Quantum-mechanical shell effects are expected to strongly enhance nuclear binding on an "island of stability" of superheavy elements. The predicted center at proton number $Z=114,120$, or $126$ and neutron number $N=184$ has been substantiated by the recent synthesis of new elements up to $Z=118$. However the location of the center and the extension of the island of stability remain vague. High-precision mass spectrometry allows the direct measurement of nuclear binding energies and thus the determination of the strength of shell effects. Here, we present such measurements for nobelium and lawrencium isotopes, which also pin down the deformed shell gap at $N=152$.
Direct mass measurements of the heaviest elements with Penning traps
2013
Abstract Penning-trap mass spectrometry (PTMS) is a mature technique to provide atomic masses with highest precision. Applied to radionuclides it enables us to investigate their nuclear structure via binding energies and derived quantities such as nucleon separation energies. Recent progress in slowing down radioactive ion beams in buffer gas cells in combination with advanced ion-manipulation techniques has opened the door to access even the elements above fermium by PTMS. Such elements are produced in complete fusion–evaporation reactions of heavy ions with lead, bismuth, and actinide targets at very low rates. Pioneering high-precision mass measurements of nobelium and lawrencium isotope…
First ionization potential of the heaviest actinide lawrencium, element 103
2016
The first ionization potential (IP1 ) of element 103, lawrencium (Lr), has been successfully determined for the first time by using a newly developed method based on a surface ionization process. The measured IP 1 value is 4.9630.08 0.07 eV. This value is the smallest among those of actinide elements and is in excellent agreement with the value of 4.963(15) eV predicted by state-of-the-art relativistic calculations also performed in this work. Our results strongly support that the Lr atom has an electronic configuration of [Rn]7s 2 5f 14 7p 1 1/2 , which is influenced by strong relativistic effects. The present work provides a reliable benchmark for theoretical calculations and also opens t…
High-precision ab initio calculations of the spectrum of Lr$^+$
2019
The planned measurement of optical resonances in singly-ionised lawrencium (Z = 103) requires accurate theoretical predictions to narrow the search window. We present high-precision, ab initio calculations of the electronic spectra of Lr$^+$ and its lighter homologue lutetium (Z = 71). We have employed the state-of-the-art relativistic Fock space coupled cluster approach and the AMBiT CI+MBPT code to calculate atomic energy levels, g-factors, and transition amplitudes and branching-ratios. Our calculations are in close agreement with experimentally measured energy levels and transition strengths for the homologue Lu$^+$ , and are well-converged for Lr$^+$ , where we expect a similar level o…