Separator for Heavy Ion Reactions

In 1994 and 1995 Dr. Darleane Hoffinan of LLNL in Cahfornia and others from Germany used the Separator for Heavy Ion Reaction Products (SHIP) at the GSI laboratory in Darmstadt, Germany, to produce two new isotopes of element 110. 

The identification of the first transuranium elements was by chemical means. In the early 1960s physical techniques were developed which allowed for detection of nuclei with lifetimes of less than one second at high sensitivity. A further improvement of the physical methods was obtained with the development of recoil separators and large area position sensitive detectors. As a prime example for such instruments, we will describe the velocity filter SHIP (Separator for Heavy-Ion reaction Products) and its detector system, which were developed at the UNILAC. The principle of separation and detection techniques used in the other laboratories is comparable. 

Schematic view of the veiocity fiiter Separator for Heavy Ion reaction Products (SHiP) in its present configuration with target wheei and detector array (Hofmann and Munzenberg 2000)...

Often the products of nuclear reactions have very short half-lives. This is especially true for the heaviest elements obtained by bombardment of heavy targets with heavy ions. To identify and characterize such short-lived nuclides, fast separations are required solvent extraction techniques are well suited to provide the required fast separations. For example, the SISAK method [68] has been successfully used in conjunction with in-line gas jet separators at heavy ion accelerators to identify short half-life actinide isotopes produced by collision of heavy atoms. The Sisak method involves use of centrifugal contactors, with phase residence times as low as tenths of a second, in conjunction with in-line radiometric detection equipment. 

Figure 8.24. Cro.s.s sections (mass yields) for the heavy ion reaction Ar — - experimental values (thick target, chemical separation) a quasiclastic processes b multinuclcon transfer c fusion followed by fission d fis.sion of heavy nuclei produced from by transfer reactions. (According to J. V. KraU, J. O. Liljenzin, A. E. Norris, C], T. Seaborg, Phys. Rev. C 13 2347 (1976).)...

Recently, the SISAK technique has been applied for the separation of new, neutron-rich neptunium isotopes formed in direct transfer reactions between 8Xe projectiles and targets of Pu at the UNI LAC heavy-ion accelerator. The SISAK system consisted of three mixer-centrifuge units and a degasser. 

The breakthrough process is the simplest for the separation of two solutes on an ion-exchange column. As the absorbed band travels down the column its front is depleted in the less well sorbed solute, whereas the other solute is enriched in this part of the band. The concentration profiles of the solutes in the effluent are S-shaped. Only the slight difference in the equilibrium constants K for the ion-exchange reactions of the light (subscript L) and heavy (subscript H) isotope ions (X) with the counterion of the resin (Y) is employed as in reaction [I] ... 

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