Search results for "Heavy element"
showing 10 items of 67 documents
Probing Sizes and Shapes of Nobelium Isotopes by Laser Spectroscopy
2018
Until recently, ground-state nuclear moments of the heaviest nuclei could only be inferred from nuclear spectroscopy, where model assumptions are required. Laser spectroscopy in combination with modern atomic structure calculations is now able to probe these moments directly, in a comprehensive and nuclear-model-independent way. Here we report on unique access to the differential mean-square charge radii of ^{252,253,254}No, and therefore to changes in nuclear size and shape. State-of-the-art nuclear density functional calculations describe well the changes in nuclear charge radii in the region of the heavy actinides, indicating an appreciable central depression in the deformed proton densi…
On the search for elements beyond Z =118. An outlook based on lessons from the heaviest known elements
2016
Recently, IUPAC approved all elements up to Z = 118 as discovered. Search experiments for the heavier elements with Z = 119 and 120 have been performed in recent years, but have so far not led to their discovery. I will review some aspects associated with the study and identification of the heaviest known elements that are relevant for future search experiments for elements beyond Z = 118 and highlight pressing issues that should be addressed, both on the experimental as well as on the theory side, to allow for performing these future experiments under improved and better informed conditions.
Search for superheavy elements in monazites using chemical enrichment
1982
Evidence for the existence of superheavy elements in monazite inclusions embedded in Madagascan mica and surrounded by giant radioactive haloes was given by Gentry et al.1 who observed photons with energies corresponding to predicted Lα1 X-ray energies of element 126 (at 27.25 keV) and also of elements 116, 124 and 127 in irradiations of such crystals with collimated proton beams. For an unambiguous identification, the detection of further members of the L X-ray series would be most important. In X-ray spectra of monazite samples these transitions are buried under the strong K X-ray peaks of the lanthanide elements. They should, however, become visible after chemical enrichment of the super…
Walter Greiner, a Pioneer in Super Heavy Element Research Historical Remarks and New Experimental Developments
2020
With his theoretical work Walter Greiner pioneered super-heavy element research. He motivated the young scientists and actively shaped the profile of the Gesellschaft fur SchwerIonenforschung, GSI, Darmstadt. We are happy that still during his lifetime we at GSI could prove some of his predictions: Fusion with magic nuclei and super heavy elements, the nuclear species existing only by shell stabilization. With the discovery of oganesson, Z = 118, the heaviest element known today, we have come to the end of super heavy-element production by the fusion of magic nuclei. In-flight separation and new experimental developments including Walter Greiner’s new ideas for SHE synthesis will be discuss…
Seaborgium's complex studies
2015
Christoph E. Dullmann reflects on the excitement, and implications, of probing the reactivity of heavy element seaborgium.
Recoil-α-fission and recoil-α–α-fission events observed in the reaction 48Ca + 243Am
2016
Products of the fusion-evaporation reaction 48Ca + 243Am were studied with the TASISpec set-up at the gas-filled separator TASCA at the GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany. Amongst the detected thirty correlated α-decay chains associated with the production of element Z=115, two recoil-α-fission and five recoil-α-α-fission events were observed. The latter five chains are similar to four such events reported from experiments performed at the Dubna gas-filled separator, and three such events reported from an experiment at the Berkeley gas-filled separator. The four chains observed at the Dubna gas-filled separator were assigned to start from the 2n-evaporation ch…
A Progress Report on Laser Resonance Chromatography
2022
Atoms 10(3), 87 (2022). doi:10.3390/atoms10030087
Production and study of chemical properties of superheavy elements
2019
Abstract Some highlight examples on the study of production and chemical properties of heaviest elements carried out mostly at GSI Darmstadt are presented. They focus on the production of some of the heaviest known elements (114Fl, 115Mc, and 117Mc), studies of non-fusion reactions, and on chemical studies of 114Fl. This is the heaviest element, for which chemical studies have been performed to date.
Development of nuclear chemistry at Mainz and Darmstadt
2018
Abstract This review describes some key accomplishments of Günter Herrmann such as the establishment of the TRIGA Mark II research reactor at Mainz University, the identification of a large number of very neutron-rich fission products by fast, automated chemical separations, the study of their nuclear structure by spectroscopy with modern detection techniques, and the measurement of fission yields. After getting the nuclear chemistry group, the target laboratory, and the mass separator group established at the Gesellschaft für Schwerionenforschung (GSI) in Darmstadt, a number of large international collaborations were organized exploring the mechanism of deeply inelastic multi-nucleon trans…
In-flight separation with gas-filled systems
1997
Abstract The application of gas-filled recoil separators in the study of fusion evaporation products from heavy ion induced reactions will be discussed. Practical methods for estimating the average magnetic rigidity of fusion products and target-like nuclei will be presented. Examples will be given of typical background intensities observed in studies of heavy elements. The merits of gas-filled devices in comparison with other in-flight separators will be discussed. Selected recent applications in the fields of heavy element research and in-beam gamma-ray spectroscopy will be presented, and finally, some future projects will be discussed.