M. Beckerman

Sub-barrier fusion ofNi58,64withNi64andGe74

Differential cross sections for evaporation residue formation following complete fusion of /sup 64/Ni and /sup 74/Ge with 171 to 215 MeV /sup 58/Ni and /sup 64/Ni ions were measured with high precision using a velocity selector together with a counter telescope. The resulting excitation functions for complete fusion ranged in magnitude from 10 ..mu..b to 300 mb. The excitation functions exhibited a strong response, at subbarrier energies, to changes in the underlying nuclear structure. We interpreted these variations as evidence that the fusion proceeds through dynamic single-particle/softness-related processes. A phenomenological analysis was performed. In the analysis, we employed the WKB method, constructed a simple interaction potential and introduced a radially-dependent effective mass. The use of the variable effective mass led to a meaningful description of our above-barrier data and to improvements towards describing our subbarrier data.

Fusion ofNi58,60,62with 113-170 MeVCa40ions

Results of measurements of the fusion excitation functions of /sup 58,60,62/Ni targets with 113 --170 MeV (lab) /sup 40/Ca ions are reported. These results are used to extract fusion barrier heights and radii by several different methods. Subbarrier fusion cross sections are analyzed in terms of static deformations. Possible importance of dynamic deformation is discussed. Conclusions as to the role of static deformation are similar to those from the /sup 35/Cl+/sup 58,60,62/Ni fusion system; a large part of the subbarrier behavior can be attributed to this cause.

Sub-barrier fusion of /sup 58,64/Ni with /sup 64/Ni and /sup 74/Ge

Differential cross sections for evaporation residue formation following complete fusion of /sup 64/Ni and /sup 74/Ge with 171 to 215 MeV /sup 58/Ni and /sup 64/Ni ions were measured with high precision using a velocity selector together with a counter telescope. The resulting excitation functions for complete fusion ranged in magnitude from 10 ..mu..b to 300 mb. The excitation functions exhibited a strong response, at subbarrier energies, to changes in the underlying nuclear structure. We interpreted these variations as evidence that the fusion proceeds through dynamic single-particle/softness-related processes. A phenomenological analysis was performed. In the analysis, we employed the WKB method, constructed a simple interaction potential and introduced a radially-dependent effective mass. The use of the variable effective mass led to a meaningful description of our above-barrier data and to improvements towards describing our subbarrier data.

Sub-barrier fusion of Ni-58, Ni-64 with Ni-64 and Ge-74

Differential cross sections for evaporation residue formation following complete fusion of /sup 64/Ni and /sup 74/Ge with 171 to 215 MeV /sup 58/Ni and /sup 64/Ni ions were measured with high precision using a velocity selector together with a counter telescope. The resulting excitation functions for complete fusion ranged in magnitude from 10 ..mu..b to 300 mb. The excitation functions exhibited a strong response, at subbarrier energies, to changes in the underlying nuclear structure. We interpreted these variations as evidence that the fusion proceeds through dynamic single-particle/softness-related processes. A phenomenological analysis was performed. In the analysis, we employed the WKB method, constructed a simple interaction potential and introduced a radially-dependent effective mass. The use of the variable effective mass led to a meaningful description of our above-barrier data and to improvements towards describing our subbarrier data.

Fusion of /sup 58,60,62/Ni with 113 --170 MeV /sup 40/Ca ions

Results of measurements of the fusion excitation functions of /sup 58,60,62/Ni targets with 113 --170 MeV (lab) /sup 40/Ca ions are reported. These results are used to extract fusion barrier heights and radii by several different methods. Subbarrier fusion cross sections are analyzed in terms of static deformations. Possible importance of dynamic deformation is discussed. Conclusions as to the role of static deformation are similar to those from the /sup 35/Cl+/sup 58,60,62/Ni fusion system; a large part of the subbarrier behavior can be attributed to this cause.

Fusion of Ni-58, Ni-60, Ni-62 with 113-170 MeV Ca-40 ions

Results of measurements of the fusion excitation functions of /sup 58,60,62/Ni targets with 113 --170 MeV (lab) /sup 40/Ca ions are reported. These results are used to extract fusion barrier heights and radii by several different methods. Subbarrier fusion cross sections are analyzed in terms of static deformations. Possible importance of dynamic deformation is discussed. Conclusions as to the role of static deformation are similar to those from the /sup 35/Cl+/sup 58,60,62/Ni fusion system; a large part of the subbarrier behavior can be attributed to this cause.