Measurement of evaporation residue cross-sections of the reaction 30Si + 238U at subbarrier energies

Journal Article · Mon Feb 26 04:00:00 EST 2007 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2713502· OSTI ID:21056783

Nishio, K; Ikezoe, H; Mitsuoka, S; Nagame, Y; Tsukada, K; Tsuruta, K ^[1]; Hofmann, S ^[2]; Hessberger, F P; Ackermann, D; Heinz, S; Khuyagbaatar, J; Kindler, B; Kojouharov, I; Lommel, B; Mazzocco, M; Schoett, H J ^[2]; Antalic, S; Saro, S ^[3]; Comas, V F; Heredia, J A ^[4]

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1. Japan Atomic Energy Agency, Tokai, Ibaraki 319-1192 (Japan)
2. Gesellschaft fuer Schwerionenforschung mbH, D-64220 Darmstadt (Germany)
3. Department of Nuclear Physics, Comenius University, SK-84215 Bratislava (Slovakia)
4. Higher Institue of Technologies and Applied Sciences, Habana 10400 (Cuba)

The reaction 30Si + 238U {yields} 268Sg* was studied at beam energies close to the Coulomb barrier. At the above barrier energy of Ec.m. = 144.0 MeV (center-of-mass energy at half thickness of the target), we measured three decay chains of 263Sg produced by evaporation of five neutrons. The cross-section was (67{sub -37}{sup +67}) pb. At subbarrier energy of Ec.m. = 133.0 MeV we measured three spontaneously fissioning nuclei which we assigned to the isotope 264Sg. The half-life of (120{sub -44}{sup +126}) ms was determined. The production cross-section was (10{sub -6}{sup +10}) pb, which is about four orders magnitude larger than the calculation based on the one-dimensional barrier penetration model in the fusion process, showing fusion enhancement caused by the prolate deformation of 238U. At Ec.m. = 128.0 MeV an upper cross-section limit of 15 pb was measured. Compared to excitation functions measured for the lighter system 16O + 238U {yields} 254Fm*, a reduction of the fusion probability was observed at low beam energies indicating increasing competition from quasifission processes.

• OSTI ID: 21056783
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 891; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA DECAY
COULOMB FIELD
EVAPORATION MODEL
EXCITATION FUNCTIONS
FERMIUM 254
HALF-LIFE
HEAVY ION FUSION REACTIONS
MEV RANGE
NEUTRONS
NUCLEAR DEFORMATION
OXYGEN 16 REACTIONS
PROBABILITY
QUASI-FISSION
SEABORGIUM 263
SEABORGIUM 264
SEABORGIUM 268
SILICON 30 REACTIONS
SPONTANEOUS FISSION
URANIUM 238 TARGET