209Bi(6He,α) reaction mechanisms studied near the Coulomb barrier using n–α coincidence measurements

Influence of single-neutron stripping on near-barrier He6+Pb208 and HeMarquínez-Durán1, Keeley2, Kemper3 et al. 2017Phys. Rev. C77390View full textAdd to dashboardCite

“…However, because there is no simple model for the breakup of 8 He, we have here limited our study to a comparison of the single-neutron-stripping coupling. We note that two-neutron stripping, i.e., the ( 6 He , 4 He) and ( 8 He , 6 He) reactions, is known to be an important contributor to the total reaction cross section for systems involving 6 He [18][19][20][21][22][23] and 8 He [24] projectiles incident on heavy targets. However, realistic calculation of this reaction is not possible due to the large positive Q values that favor population of states in the 210 Pb residual nucleus at excitation energies where there is little or no structure information available.…”

Near and sub-barrier reactions of 8B

“…This is similar to the situation for 6 He reactions, in which the sum of the fusion and breakup/transfer yields equals the total reaction cross section. However, in the 6 He case, direct reactions, and particularly two-neutron transfer [3], dominate the total reaction cross section near the barrier, while in the case of 8 B the fusion and direct yields are more comparable.…”

“…This is surprising since it is known that the two-neutron-transfer cross section for 6 He is remarkably large near to and below the Coulomb barrier [3], while the breakup cross section of 8 B is considerably smaller [14,15]. The latter was extensively studied in the context of the coupled discretized continuum channels (CDCC) method [16].…”

“…This separation was accomplished for the 6 He+ 209 Bi reaction in a series of experiments [3][4][5] carried out at the TwinSol facility [6]. Other examples are discussed in Ref.…”

Reactions with the double-Borromean nucleusHe8

“…This in turn would also be expected to influence the reaction mechanism. Large transfer cross-sections have been reported for 6 He beams on 65 Cu [14,15], 64 Zn [16], 197 Au [17], 209 Bi [18,19] and 238 U targets [20,21]. Refs.…”