A Pulsed Gas Stripper for Stripping of High-Intensity, Heavy-Ion Beams at 1.4 MeV/u at the GSI UNILAC

The GSI UNILAC in combination with SIS18 will serve as a high-current, heavy-ion injector for the future FAIR. It has to meet high demands in terms of beam brilliance at a low duty factor (100 mus beam pulse length, 2.7 Hz repetition rate). An advanced 1.4 MeV/u gas stripper setup has been developed, aiming at an enhanced yield into the required charge states. The setup delivers short, high-density gas pulses in synchronization with the beam pulse. This provides an increased gas density at a reduced gas load for the differential pumping system. In recent measurements, high-intensity, heavy-ion beams of U⁴⁺ were successfully stripped and separated for the desired charge state. The modified stripper setup, as well as major results, are presented, including a comparison to the present gas stripper based on a N₂ gas-jet. The stripping efficiency into the desired 28⁺ charge state was significantly increased by up to 60 % using a hydrogen stripper target while the beam quality remained similar

In-situ formation, thermal decomposition, and adsorption studies of transition metal carbonyl complexes with short-lived radioisotopes

Abstract We report on the in-situ synthesis of metal carbonyl complexes with short-lived isotopes of transition metals. Complexes of molybdenum, technetium, ruthenium and rhodium were synthesized by thermalisation of products of neutron-induced fission of 249Cf in a carbon monoxide-nitrogen mixture. Complexes of tungsten, rhenium, osmium, and iridium were synthesized by thermalizing short-lived isotopes produced in 24Mg-induced fusion evaporation reactions in a carbon monoxide containing atmosphere. The chemical reactions took place at ambient temperature and pressure conditions. The complexes were rapidly transported in a gas stream to collection setups or gas phase chromatography devices. The physisorption of the complexes on Au and SiO2 surfaces was studied. We also studied the stability of some of the complexes, showing that these start to decompose at temperatures above 300 ℃ in contact with a quartz surface. Our studies lay a basis for the investigation of such complexes with transactinides.</jats:p