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RESEARCH PRODUCT

Recoil-isomer tagging techniques at RITU

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description

Techniques have been developed to study isomeric states in nuclei with the use of RITU (gas filled separator) at the University of Jyvaskyla. The first was the recoil-isomer tagging technique initially, utilised by D.M. Cullen to study the K π = 8− isomeric state in 138Gd [1]. The juro-sphere array was employed in conjunction with ritu and a focal plane array which consisted of several Compton-suppressed Germanium detectors, placed in close geometry around a multi wire proportional counter (mwpc) and a silicon strip detector used for the implantation of recoiling nuclei. This technique correlates prompt and delayed γ-ray transitions across isomeric states and identifies the lifetime of the isomer. The main constraint of this technique is the timing electronics. Only isomers with a half-life greater than the flight time through RITU(~ 300ns) and less than the collection time of the tdc’s (32 μs) can be identified. This time range and hence technique is ideal for the region of mass A = 140 near proton drip line nuclei which have small production cross-sections in comparison to their more neutron rich neighbours and lack charged particle emission suitable for recoil-decay-tagging. Subsequent experiments to ref.