Regime II of fusion process in the collision of32S with magnesium isotopes

Autor: M. L. Sperduto, Sl. Cavallaro
Rok vydání: 1990
Předmět:
Zdroj: Il Nuovo Cimento A. 103:429-446
ISSN: 1826-9869
0369-3546
Popis: Measurements of the residue cross-sections for the32S+24,25,26Mg reactions have been performed in the rangeElab=(140÷175)MeV, to study the amount of limitation undergone by fusion in regime II. Residual nuclei have been identified by means of the in beam γ-spectroscopy method. Comparison of evaporation residue cross-sections with statistical calculations shows an average overall agreement although large discrepancies are found for some outgoing channels. Fusion excitation functions confirm previous evidences on the onset of regime II atElab∼145 MeV. This exhibits considerable limitations to the fusion process. Considering the whole set of the data, the barrier penetration model reproduces the lowenergy behaviour with a slight overestimation of experimental results. Values oflcr=35▄ for the angular momentum andRcr≈(6÷6.2) fm for the critical distance are respectively found. The surface friction model gives very good agreement in the low-energy part, but its calculations are larger than the experimental values in regime II. Some evidence is reported in the literature which could indicate that a fusion-fission process is mainly responsible for the deficit on the evaporation residue cross-section.
Databáze: OpenAIRE
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