Mechanism of neon-induced reactions studied between 7.5 and 20 MeV/nucleon: Inclusive cross sections

Influence of projectile cluster properties on fragment emission in incomplete-fusion reactions

“…The expressions strongly depend on the binding energy Eb and exhibit a symmetry with respect to the projectile fragments. The comparison with experimental data [6,13] shows that the parallel width of the fragment spectrum and the relative fragment yields are influenced by the cluster properties of the projectile.…”

“…It means that the direct-transfer (or breakup-fusion) mechanism dominates over the pure projectile breakup. Sequential processes [4,[6][7][8][9] also take place in the reactions. High-excited heavy projectile-like fragments, formed by the direct transfer as a first step, undergo a sequential decay mainly by alpha-particle emission which is due to its low threshold.…”

“…A special attention has been paid to the possible reaction mechanisms contributing to the emission cross section of different fragments. A more detailed information about them comes from particle-gamma [1][2][3][4] and particle-particle [5][6][7] coincidence experiments. The experimental data show that the ejectile is a fragment of the projectile and also that in most of the events the remainder is captured by the target.…”

“…Apparently, the shape of the spectrum of the fragments which are due to the direct-transfer process can be obtained from the high-energy part of the spectrum. The group from Hahn-Meitner Institute [6][7][8][9] has measured the multiplicity of the emitted neutrons in coincidence with the fragments to separate the breakup contributions from the spectra. The analyses of the coincidence data, however, are complicated due to the mixing of a part of the direct-transfer component of the neutron-multiplicity distribution corresponding to the high-energy tail of the fragment spectrum with the breakup component.…”

“…In order to avoid this asymmetry Homeyer et al [7] accepted a dependence on the size of the heavy fragment no matter which of the fragments is the ejectile. The cluster-stripping model with phenomenological corrections for the neutron pickup from the target is applied successfully [7] to the data [6] of 2~ +~97Au reaction at beam energies 150 MeV and 290 MeV for fragments with masses As>10 and charges Zy => 5. In contrast to Friedman's model [16] the spectroscopic factor is taken to be weakly varying over the range of the considered fragments which strongly reduces the variation of relative isotope yields in comparison with Friedman predictions.…”