A systematic survey of the accurate measurements of heavy-ion fusion cross sections at extreme sub-barrier energies is performed using the coupled-channels(CC)theory that is based on the proximity formalism.This work ...A systematic survey of the accurate measurements of heavy-ion fusion cross sections at extreme sub-barrier energies is performed using the coupled-channels(CC)theory that is based on the proximity formalism.This work theoretically explores the role of the surface energy coefficient and energy-dependent nucleus-nucleus proxim-ity potential in the mechanism of the fusion hindrance of 14 typical colliding systems with negative Q-values,in-eluding ^(11a)B+^(197)AU,^(12)C+^(198)Pt,^(16)O+^(208)Pb,^(28)Si+^(94Mo),^(48)Ca+^(96)Zr,^(28Si+)^(64)Ni,^(58)Ni+^(58)Ni+,^(60)Ni+^(89)Y,^(12)C+^(204)Pb,^(36)S+^(64)Ni,^(36)S+^(90)Zr,^(40)Ca+^(90)Zr,^(40)Ca+^(40Ca)and ^(48)Ca+^(48)Ca,,as well as five typical colliding systems with positive Q-values,ineluding ^(12)C+^(30)Si,^24Mg+^(30)Si,^(36)Si+^(48)Ca, and ^(40)Ca+^(48)Ca.It is shown that the outcomes based on the proximity potential along with the above-mentioned physical effects achieve reasonable agreement with the experimentally observed data of the fusion cross sections(Tfus(£),astrophysical S(E)factors,and logarithmic derivatives L(E)in the energy region far below the Coulomb barrier.A discussion is also presented on the performance of the present theoretical approach in reproducing the experimental fusion barrier distributions for different colliding systems.展开更多
文摘A systematic survey of the accurate measurements of heavy-ion fusion cross sections at extreme sub-barrier energies is performed using the coupled-channels(CC)theory that is based on the proximity formalism.This work theoretically explores the role of the surface energy coefficient and energy-dependent nucleus-nucleus proxim-ity potential in the mechanism of the fusion hindrance of 14 typical colliding systems with negative Q-values,in-eluding ^(11a)B+^(197)AU,^(12)C+^(198)Pt,^(16)O+^(208)Pb,^(28)Si+^(94Mo),^(48)Ca+^(96)Zr,^(28Si+)^(64)Ni,^(58)Ni+^(58)Ni+,^(60)Ni+^(89)Y,^(12)C+^(204)Pb,^(36)S+^(64)Ni,^(36)S+^(90)Zr,^(40)Ca+^(90)Zr,^(40)Ca+^(40Ca)and ^(48)Ca+^(48)Ca,,as well as five typical colliding systems with positive Q-values,ineluding ^(12)C+^(30)Si,^24Mg+^(30)Si,^(36)Si+^(48)Ca, and ^(40)Ca+^(48)Ca.It is shown that the outcomes based on the proximity potential along with the above-mentioned physical effects achieve reasonable agreement with the experimentally observed data of the fusion cross sections(Tfus(£),astrophysical S(E)factors,and logarithmic derivatives L(E)in the energy region far below the Coulomb barrier.A discussion is also presented on the performance of the present theoretical approach in reproducing the experimental fusion barrier distributions for different colliding systems.
