Production and decay of element 114: high cross sections and the new nucleus 277Hs.
The fusion-evaporation reaction 244Pu(48Ca,3-4n){288,289}114 was studied at the new gas-filled recoil separator TASCA. Thirteen correlated decay chains were observed and assigned to the production and decay of {288,289}114. At a compound nucleus excitation energy of E{*}=39.8-43.9  MeV, the 4n evaporation channel cross section was 9.8{-3.1}{+3.9}  pb. At E^{*}=36.1-39.5  MeV, that of the 3n evaporation channel was 8.0{-4.5}{+7.4}  pb. In one of the 3n evaporation channel decay chains, a previously unobserved α branch in 281Ds was observed (probability to be of random origin from background: 0.1%). This α decay populated the new nucleus 277Hs, which decayed by spontaneous fission after a lifetime of 4.5 ms.
Düllmann
Ch E
ChE
GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany. c.e.duellmann@gsi.de
Schädel
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Yakushev
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Türler
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Eberhardt
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Kratz
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Ackermann
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Andersson
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Block
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Brüchle
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Dvorak
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Essel
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Ellison
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Even
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Gates
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Gorshkov
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Graeger
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Gregorich
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Hartmann
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Herzberg
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Hessberger
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Hild
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Hübner
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Jäger
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Khuyagbaatar
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Kindler
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Krier
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Kurz
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Lahiri
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Liebe
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Lommel
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Maiti
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Nitsche
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Omtvedt
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Parr
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Rudolph
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Runke
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Schausten
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Schimpf
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Semchenkov
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Steiner
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Thörle-Pospiech
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Uusitalo
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Wegrzecki
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Wiehl
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