Nuclear orientation in the reaction {sup 34}S+{sup 238}U and synthesis of the new isotope {sup 268}Hs

Journal Article · Sun Aug 15 00:00:00 EDT 2010 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.82.024611· OSTI ID:21419444

Nishio, K; Ikezoe, H; Mitsuoka, S; Nagame, Y; Nishinaka, I ^[1]; Hofmann, S ^[2]; Hessberger, F P; Ackermann, D; Duellmann, Ch E; Heinz, S; Heredia, J A; Khuyagbaatar, J; Kindler, B; Kojouharov, I; Lommel, B; Mann, R; Schaedel, M ^[2]; Antalic, S; Saro, S ^[3]; Aritomo, Y ^[1]

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1. Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan)
2. GSI Helmholtzzentrum fuer Schwerionenforschung, D-64291 Darmstadt (Germany)
3. Department of Nuclear Physics and Biophysics, Comenius University, SK-84248 Bratislava (Slovakia)

The synthesis of isotopes of the element hassium was studied using the reaction {sup 34}S+{sup 238}U{yields}{sup 272}Hs{sup *}. At a kinetic energy of 163.0 MeV in the center-of-mass system we observed one {alpha}-decay chain starting at the isotope {sup 267}Hs. The cross section was 1.8{sub -1.5}{sup +4.2} pb. At 152.0 MeV one decay of the new isotope {sup 268}Hs was observed. It decays with a half-life of 0.38{sub -0.17}{sup +1.8} s by 9479{+-}16 keV {alpha}-particle emission. Spontaneous fission of the daughter nucleus {sup 264}Sg was confirmed. The measured cross section was 0.54{sub -0.45}{sup +1.3} pb. In-beam measurements of fission-fragment mass distributions were performed to obtain information on the fusion probability at various orientations of the deformed target nucleus. The distributions changed from symmetry to asymmetry when the beam energy was changed from above-barrier to sub-barrier values, indicating orientation effects on fusion and/or quasifission. It was found that the distribution of symmetric mass fragments originates not only from fusion-fission, but has a strong component from quasifission. The result was supported by a calculation based on a dynamical description using the Langevin equation, in which the mass distributions for fusion-fission and quasifission fragments were separately determined.

• OSTI ID: 21419444
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 82, Issue 2; Other Information: DOI: 10.1103/PhysRevC.82.024611; (c) 2010 The American Physical Society; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA DECAY
ALPHA PARTICLES
ASYMMETRY
CENTER-OF-MASS SYSTEM
CROSS SECTIONS
EMISSION
HALF-LIFE
HASSIUM 267
HASSIUM 272
ISOTOPE PRODUCTION
LANGEVIN EQUATION
MASS
MASS DISTRIBUTION
MEV RANGE 100-1000
QUASI-FISSION
SEABORGIUM 264
SPONTANEOUS FISSION
SYMMETRY
SYNTHESIS
URANIUM 238
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
CHARGED PARTICLES
DECAY
DISTRIBUTION
ENERGY RANGE
EQUATIONS
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
FISSION
HASSIUM ISOTOPES
HEAVY ION REACTIONS
HEAVY NUCLEI
IONIZING RADIATIONS
ISOTOPES
MEV RANGE
MILLISECONDS LIVING RADIOISOTOPES
NUCLEAR DECAY
NUCLEAR REACTIONS
NUCLEI
RADIATIONS
RADIOISOTOPES
SEABORGIUM ISOTOPES
SECONDS LIVING RADIOISOTOPES
SPATIAL DISTRIBUTION
SPONTANEOUS FISSION RADIOISOTOPES
URANIUM ISOTOPES
YEARS LIVING RADIOISOTOPES