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[en] For heavy element studies at GSI, lanthanide and actinide targets have been prepared by molecular plating. The deposition occurs from an isopropanolic solution at 1000-1200 V with current densities of a few mA/cm². Several lanthanide targets have been prepared for test experiments. With ^natGd deposited on a 10 μm thick Be backing foil a target density of 1100 μg/cm² could be achieved. Gd-targets were used for the production of α-emitting isotopes of Os, the homologue of hassium (Hs; Z=108), in order to develop a chemical separation procedure for Hs. ²⁴⁸Cm targets with densities up to 730 μg/cm² have been produced for recent experiments to investigate the chemical behaviour of Hs. Here, a rotating wheel system with a multi-target device has been applied enabling higher beam intensities, compared to a stationary target. The targets were irradiated with a pulsed ²⁶Mg⁵⁺ beam applying beam currents up to 6.6 μA_electr. An α-spectroscopic investigation of the irradiated Cm-targets showed that the Cm-material is not evenly distributed over the entire target area. Very often, for heavy element investigations, chemical separation procedures are required to ensure high purity of the deposited actinide materials

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[en] For the preparation of actinide targets electrochemical methods have been used. Electrolytic deposition in form of the actinide hydroxide on a Ta- or Ti-backing is performed from an aqueous solution, applying current densities up to several A/cm2. In the case of Be or Al as backing material, molecular plating was applied. Here, the deposition from an organic solution (usually isopropanol) with current densities of only a few mA/cm2 and voltages up to 1000 V occurs. With these techniques target densities up to 1 mg/cm2 are possible. In most cases, prior to deposition, chemical separation procedures are required to ensure high purity of the target material. Targets with thicknesses ranging from fg/cm2 up to mg/cm2 for the actinides Ac to Es have been produced. A brief survey for the applications of actinide targets in chemical and physical studies is given

[en] The transactinide element ²⁶¹Rf was produced for the first time at the PSI Phillips cyclotron in the reaction ²⁴⁴Pu(²²Ne,5n). At bombarding energy of 116 MeV the production cross section was 3 nb. (author) 2 figs., 1 tab., 1 ref

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[en] Carrier-free short-lived nuclides are employed in many different fields of modern nuclear chemistry. The two main production strategies are either thermal neutron-induced fission of ²³⁵U or ²³⁹Pu at nuclear reactors or spallation neutron sources or charged particle-induced nuclear reactions at accelerator facilities. An alternative method is to use a spontaneously fissioning nuclide. A facility applying this technique ('Miss Piggy') was built at the University of Berne (Switzerland). Californium-252 (²⁵²Cf), which has a 3% fission branch and a half-life of 2.645 a, is used for the production of short-lived fission products that are stopped in an adjacent recoil chamber. Short-lived nuclides are transported out of the recoil chamber using the well-known gas-jet technique. Over 100 nuclides have been identified so far and used in different applications. Since such a device does not require any large facility and is easy to operate it serves well the needs of typical university laboratories

No abstract available