[en] The exciting results search for superheavy elements which have been achieved in the recent years have triggered a broad range of activities. Apart from experiments to attempt the synthesis of new elements, nuclear structure investigations in the transactinide region has become possibly for Z up to 108 or 110. Heavy element chemistry has successfully placed Hs in the periodic table and is no attacking element 112. The development of accelerators and experimental methods promises advances to enable the extension of these investigations in regions closer to the ''island of stability''. Mass measurements using ion traps and neutron rich unstable beam species for the systematic investigation of nuclear structure and reaction mechanisms for heavy neutron rich system are believed to complete the variety of tools in future

[en] The search for superheavy elements (SHE) has yielded exciting results for both the 'cold fusion' approach with reactions employing Pb and Bi targets and the ''hot fusion'' reactions with ⁴⁸Ca beams on actinide targets. The most recent activities at GSI were the successful production of a more neutron rich isotope of element 112 in the reaction ⁴⁸Ca+²³⁸U confirming earlier result from FLNR, and the attempt to synthesize an isotope with Z 120 in the reaction ⁶⁴Ni+²³⁸U. Apart from the synthesis of new elements, advanced nuclear structure studies for heavy and super heavy elements promise a detailed insight in the properties of nuclear matter under the extreme conditions of high Z and A. The means are evaporation residue(ER)-α-α and -α-γ coincidence techniques applied after separation of the reaction products from the beam. Recent examples of interesting physics to be discovered in this region of the chart of nuclides are the investigation of K-isomers observed for ^252,254No and indicated for ²⁷⁰Ds. Fast chemistry and precision mass measurements deliver in addition valuable information on the fundamental properties of the SHE.

[en] After more than half a century of research addressing the synthesis and nuclear structure of superheavy nuclei (SHN), a boost for its progress is expected from the advent of new instrumentation. An order of magnitude in beam intensity increase is envisaged to be provided by new powerful accelerators such as the new DC280 cyclotron at the SHE factory of FLNR/JINR or the superconducting linac at SPIRAL2 of GANIL. In addition, new ion-optical installations like the separator-spectrometer set-up S³ with two complementary detection systems SIRIUS and LEB will provide a substantial sensitivity increase for classically pursued routes like decay spectroscopy after separation (DSAS), and alternative and complementary methods such as high precision mass measurements and laser spectroscopy. Decay spectroscopy has proven in the past to be a powerful tool to study the low-lying nuclear structure of heavy and superheavy nuclei. Single particle levels and other structure features like K isomerism, being important in the fermium-nobelium region as well as for the route towards spherical shell stabilised SHN, have been investigated almost up to the limit posed by the sensitivity of the present-day instrumentation. Precision mass measurements and laser spectroscopy will offer the possibility to study alternative features such as binding energies, charge radii and quadrupole moments. At the magnetic spectrometer VAMOS of GANIL with the recently improved mass resolution and the development of Z identification, deep-inelastic reactions like multi-nucleon transfer can be used to reach more neutron-rich nuclei in the region of light actinides, possibly being extended towards higher Z. (authors)

[en] The search for superheavy elements (SHE) has yielded exciting results for both the 'cold fusion' approach with reactions employing Pb and Bi targets and the 'hot fusion' reactions with ⁴⁸Ca beams on actinide targets. The most recent activities at GSI were the successful production of a more neutron rich isotope of element 112 in the reaction ⁴⁸Ca+²³⁸U confirming earlier result from FLNR, and the attempt to synthesize an isotope with Z=120 in the reaction ⁶⁴Ni+²³⁸U. Apart from the synthesis of new elements, advanced nuclear structure studies for heavy and superheavy elements promise a detailed insight in the properties of nuclear matter under the extreme conditions of high Z and A. The means are evaporation residue (ER)-α-α and -α-γ coincidence techniques applied after separation of the reaction products from the beam. Recent examples of interesting physics to be discovered in this region of the chart of nuclides are the investigation of K-isomers observed for ^252,254No and indicated for ²⁷⁰Ds. Fast chemistry and precision mass measurements deliver in addition valuable information on the fundamental properties of the SHE. In the process of continuous development and improvement of the experimental methods, which is mandatory to address the challenges of ever lower cross-sections asking for ever higher beam intensities, the target technology plays an important role.

[en] The elements with the atomic numbers 107-112 have been synthesized and unambiguously identified at the velocity filter SHIP at GSI. The technique allowing for this successful experimental program is the combination of the detection of correlations between evaporation residues and subsequent a-decays with a powerful separator. Systematic investigations, the construction of decay chain networks and mass measurements are some of the possible approaches to study the decay chains tentatively attributed to the isotopes of the elements 114 and 116 at Dubna, which are, in contrast to those observed at GSI, not connected to α-decays of known isotopes. The sensitivity limit of the set-up at GSI has reached the 1pb level. For systematic investigation in this region of extremely low cross section and to synthesize nuclei of higher Z this limit has to be pushed to even lower values. An extensive development program is pursued at SHIP in order to reach at least an order of magnitude lower cross sections. Apart from target cooling and separator development a super conducting CW linear accelerator is studied to reach this goal. To design a successful experimental program for the possible discovery of new elements the nuclear structure of the heaviest nuclei has to be understood as well as the reaction mechanism which leads to their production in heavy ion reactions. We have initiated series of systematic studies for both subjects

[en] Dieter Ackermann explains why element 110 occupies a significant place in the superheavy corner of the periodic table. (author)

[en] In this contribution we describe the production and application of uranium targets for synthesis of heavy elements. The targets are prepared from uranium fluoride (UF₄) and from metallic uranium with thin carbon foils as backing. Targets of UF₄ were produced by thermal evaporation in a similar way as the frequently applied targets out of Bi, Bi₂O₃, Pb, PbS, SmF₃, and NdF_3, prepared mostly from isotopically enriched material [Birgit Kindler, et al., Nucl. Instr. and Meth. A 561 (2006) 107; Bettina Lommel, et al., Nucl. Instr. and Meth. A 561 (2006) 100]. In order to use more intensive beams and to avoid scattering of the reaction products in the target, metallic uranium is favorable. However, evaporation of metallic uranium is not feasible at a sustainable yield. Therefore, we established magnetron sputtering of metallic uranium. We describe production and properties of these targets. First irradiation tests show promising results

[en] Recent developments of experimental techniques suited for α-, γ- and CE spectroscopy now allow to study nuclear structure in the region of trans-fermium nuclei. This opened the door to investigate nuclear structure under extreme conditions of heaviest nuclei (Z>100,A>250). Most interesting examples are studies of K-isomers. Experiments aimed to investigate such phenomena provide important information on the nuclear structure of the heaviest elements and are stringent tests for the quality of nuclear models. In this contribution the results from studies of multi-quasi-particle isomeric states in ²⁵³No and ²⁵⁵Lr performed at SHIP are presented in detail. Both nuclei are first odd-mass isotopes in the trans-fermium region for which high K-isomers were observed. By decay of the high K-isomer in ²⁵³No a rotational band was populated, which was not seen in previous in-beam studies. Additionally, also the recent results on the single particle level systematics for the N=149, 151 and 153 isotones are presented.

[en] Beta-delayed fission is a rare process in which the beta-decaying precursor populates relatively low-excited state in its decay daughter, which may then fission. This allows to study low-energy fission properties e.g. the isospin dependence of the fission barriers. It is currently believed that the beta-delayed fission process is crucial for understanding the r-process path and for the production of the heaviest elements. In the presentation, the recent experiments performed at the velocity filter SHIP (GSI) and at the mass-separator ISOLDE (CERN) will be discussed. In these experiments, the ECDF decay was unambiguously observed in several very neutron-deficient nuclides in the Pb region (^192,194At and ¹⁸⁰Tl). ECDF probability and total kinetic energy were determined. Surprisingly, an asymmetric mass distribution of fission fragments was observed in ECDF of ¹⁸⁰Tl. Preliminary analysis also shows that the cold fission (no neutron emission) might be the main decay channel in the ECDF decay of this nucleus.

[en] The isotopes ^255,256,258Rf were produced in the fusion -evaporation reactions ⁵⁰Ti + ^207,208Pb and ⁵⁰Ti + ²⁰⁹Bi at GSI Darmstadt, using the velocity filter SHIP. Total kinetic energies of fragments from spontaneous fission for these isotopes were evaluated with a correction to pulse-height defect. (authors)