Suppression of complete fusion due to breakup in the reactionsB10,11+Bi209

Abstract

Above-barrier cross sections of α-active heavy reaction products, as well as fission, were measured for the reactions of 10,11 B with 209 Bi. Detailed analysis showed that the heavy products include components from incomplete fusion as well as complete fusion (CF), but fission originates almost exclusively from CF. Compared with fusion calculations without breakup, the CF cross sections are suppressed by 15% for 10 B and 7% for 11 B. A consistent and systematic variation of the suppression of CF for reactions of the weakly bound nuclei 6,7 Li, 9 Be, 10,11 B on targets of 208 Pb and 209 Bi is found as a function of the breakup threshold energy.

Breakup locations: Intertwining effects of nuclear structure and reaction dynamics

“…Indeed, the relationship [8] between observed suppression, quantified by 1 − F CF with F CF being the fraction of complete fusion suppression, and the energy required for direct breakup, shown in Fig. 1, seemed to support this idea.…”

“…It is clear that in addition to direct breakup into α and t clusters, breakup via other modes is significant [14]. The transferinduced breakup modes arise as the nuclei that are populated following nucleon transfer are themselves weakly bound or unstable e.g., 8 Be formed following proton pickup breaks up into α − α, and 5 Li formed following 2n stripping breaks into α−p. These experiments, and those that followed using lighter targets, have all shown the dominance of transfer triggered breakup.…”

“…Using the experimentally determined average barrier energy, it was shown that above-barrier complete fusion cross-sections of the weakly-bound nucleus 9 Be + 208 Pb is suppressed [2] compared with the expectations of well bound nuclei. Complete fusion suppression has since been seen in many reactions with weakly bound stable nuclei [3][4][5][6][7][8][9]. However, studies on medium-mass and light target nuclei are sparse as experimentally it is difficult to separate complete fusion (experimentally defined as capture of the full charge of the projectile) from incomplete fusion (only part of the projectile charge is captured).…”

Projectile - Mass asymmetry systematics for low energy incomplete fusion

“…Understanding the dynamics of light-heavy-ion (A ≥ 20) induced low energy incomplete fusion (ICF) gained significant interest in recent years [1][2][3][4][5][6][7][8][9][10]. The most dominating mode of reaction from near-to above-barrier energies is complete fusion (CF) in which entire projectile fuses with target nucleus and leads to a completely fused composite system essentially via single route.…”

Theoretical study of fusion reactions 32S + 94,96Zr and 40Ca + 94,96Zr and quadrupole deformation of 94Zr

“…The study of fusion reaction mechanism is also of fundamental importance for understanding the synthesis of superheavy elements, properties of weakly bound nuclei, and symmetry energy of the nuclear equation of state [8][9][10][11][12][13][14][15][16][17] Up to now, lots of important information about fusion dynamics at energies near the Coulomb barrier, especially at sub-barrier energies, are obtained through experimental and theoretical studies, such as the fusion hindrance phenomenon at extreme low energies-a steep falloff of the fusion cross sections [18][19][20][21][22][23], the role of the neutron transfer effect in the fusion [24][25][26][27], the breakup effect on the fusion reactions process [28][29][30][31][32][33][34][35], etc..…”