0000000001257062
AUTHOR
K. Rusek
Effects of weakly coupled channels on quasielastic barrier distributions
Heavy-ion collisions often produce fusion barrier distributions with structures displaying a fingerprint of couplings to highly collective excitations. Similar distributions can be obtained from large-angle quasielastic scattering, although in this case, the role of the many weak direct-reaction channels is unclear. For $^{20}\mathrm{Ne}+^{90}\mathrm{Zr}$, we have observed the barrier structures expected for the highly deformed neon projectile; however, for $^{20}\mathrm{Ne}+^{92}\mathrm{Zr}$, we find significant extra absorption into a large number of noncollective inelastic channels. This leads to smearing of the barrier distribution and a consequent reduction in the ``resolving power'' o…
Weak channels in backscattering of20Ne onnatNi,118Sn, and208Pb
To further our understanding of the influence of weakly coupled channels on the distribution of Coulomb barrier heights, we have measured transfer cross sections for ${}^{20}$Ne ions backscattered from ${}^{\mathrm{nat}}$Ni, ${}^{118}$Sn, and ${}^{208}$Pb targets at near-barrier energies. The $Q$ value spectrum in the case of ${}^{208}$Pb target has been determined too. The transfer channels appear to be especially important for ${}^{208}$Pb, whose double-closed-shell nature leads to a relatively low level density for noncollective inelastic excitations.
Cluster-transfer reactions with radioactive beams: A spectroscopic tool for neutron-rich nuclei
An exploratory experiment performed at REX-ISOLDE to investigate cluster-transfer reactions with radioactive beams in inverse kinematics is presented. The aim of the experiment was to test the potential of cluster-transfer reactions at the Coulomb barrier as a mechanism to explore the structure of exotic neutron-rich nuclei. The reactions Li7(Rb98,αxn) and Li7(Rb98,txn) were studied through particle-γ coincidence measurements, and the results are presented in terms of the observed excitation energies and spins. Moreover, the reaction mechanism is qualitatively discussed as a transfer of a clusterlike particle within a distorted-wave Born approximation framework. The results indicate that cl…
Weak channels in backscattering of ^{20}Ne on ^{nat}Ni, ^{118}Sn, and ^{208}Pb
To further our understanding of the influence of weakly coupled channels on the distribution of Coulomb barrier heights, we have measured transfer cross sections for 20Ne ions backscattered from natNi, 118Sn, and 208Pb targets at near-barrier energies. The Q value spectrum in the case of 208Pb target has been determined too. The transfer channels appear to be especially important for 208Pb, whose double-closed-shell nature leads to a relatively low level density for noncollective inelastic excitations. peerReviewed