Strong influence of the entrance channel on the formation of compound nuclei {sup 216,222}Th* and their evaporation residues

Journal Article · Thu Dec 15 04:00:00 EST 2005 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PhysRevC.72.064614· OSTI ID:20771123

Fazio, G; Giardina, G; Mandaglio, G; Ruggeri, R; Muminov, A I; Nasirov, A K; Oganessian, Yu Ts; Popeko, A G; Sagaidak, R N; Yeremin, A V; Hofmann, S; Hanappe, F; Stodel, C ^[1]; GANIL, 14076 Caen ^[2]

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1. INFN, Sezione di Catania, and Dipartimento di Fisica dell'Universita di Messina, 98166 Messina (Italy)
2. France

The dynamical effects of the entrance channel on the formation of the evaporation residues are studied by analyzing the {sup 40}Ar+{sup 176}Hf, {sup 86}Kr+{sup 130,136}Xe, {sup 124}Sn+{sup 92}Zr, and {sup 48}Ca+{sup 174}Yb reactions leading to the {sup 216}Th* and {sup 222}Th* compound nuclei. We find that the difference between the evaporation residue cross sections for the reactions leading to the same compound nucleus is caused by the different angular momentum distributions of the partial fusion cross sections {sigma}{sub fus}{sup l}(E{sub c.m.}). The strong dependence of the fusion angular momentum distribution on the mass (charge) asymmetry and shell structure of reactants is demonstrated. The effect of the A/Z ratio for the {sup 86}Kr+{sup 130,136}Xe reactions is discussed. The dynamical conditions of capture affect the competition between complete fusion and quasifission and, consequently, the shape of the angular momentum distribution of the compound nucleus. By this way the peculiarities of the entrance channel also affect the fission-evaporation competition of the excited intermediate nuclei along the deexcitation cascade of the compound nucleus and, consequently, the evaporation residue formation.

• OSTI ID: 20771123
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 6 Vol. 72; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANGULAR MOMENTUM
ARGON 40 REACTIONS
ASYMMETRY
CALCIUM 48 REACTIONS
CAPTURE
COMPOUND NUCLEI
CROSS SECTIONS
DISTRIBUTION
FISSION
HAFNIUM 176 TARGET
KRYPTON 86 REACTIONS
QUASI-FISSION
THORIUM 216
THORIUM 222
TIN 124 REACTIONS
XENON 130 TARGET
XENON 136 TARGET
YTTERBIUM 174 TARGET
ZIRCONIUM 92 TARGET