Analysis Of Elastic Scattering Data Research Articles

Role of the shape deformation in 12C + 12C fusion at sub-Coulomb energies

The fusion cross section of 12C+12C system at the energies of astrophysical interest is calculated in the framework of barrier penetration model taking into account the deformed shape of interacting nuclei. In particular, the quadrupole surface deformation of both projectile and target nuclei has been included during the fusion process. The real and imaginary parts of nucleus-nucleus interactions performed using the Woods-Saxon square and Woods-Saxon functions, respectively have been carefully tested by 12C-12C elastic scattering data analysis before employed to evaluate the astrophysical S factors (the fusion cross sections). The optical model results of elastic angular distributions are consistent with the experimental data. Within the barrier penetration model, the real part of the obtained optical potential gives a good description of the non-resonant astrophysical S factor. It turns out that the taking into account of quadrupole deformation of 12C nuclei increases the astrophysical S factor at energies below Coulomb barrier.

Low energy deuteron-induced reactions on Fe isotopes

The activation cross sections for production of $^{51}\mathrm{Cr}$, $^{52,54,56}\mathrm{Mn}$, $^{59}\mathrm{Fe}$, and $^{55,56,57,58}\mathrm{Co}$ radioisotopes in deuteron-induced reactions on natural Fe were measured at deuteron energies up to 20 MeV. Then, within an extended analysis of deuteron interactions with ${}^{\mathrm{nat}}$Fe, all processes from elastic scattering until the evaporation from fully equilibrated compound system have been taken into account. Following the available elastic-scattering data analysis that supports the deuteron optical potential for reaction cross sections calculations, increased attention is paid especially to the breakup (BU) mechanism and direct reactions (DR). The deuteron activation cross-section analysis is completed by consideration of the preequilibrium and compound-nucleus contributions, corrected for decrease of the total reaction cross section due to the leakage of the initial deuteron flux towards BU and DR processes. The overall agreement of the measured data and model calculations validates the description of nuclear mechanisms taken into account, particularly the strong effects of direct interactions that have still not been appropriately considered within previous deuteron activation evaluations.

Analysis of Deuteron Breakup and Induced Activation on Medium Nuclei

An extended analysis of the nuclear reaction mechanisms involved within deuterons interaction with Co and Nb is presented. First, the available elastic-scattering data analysis provided the optical potential for reaction cross sections calculations. An increased effort has been devoted to the breakup mechanism, both the elastic breakup and the breakup fusion contributions to the different activation cross sections being carefully considered. Next, the direct reaction contributions, namely the stripping and pick-up reaction cross sections have been calculated. Finally, the preequilibrium and compound-nucleus cross-section calculation, corrected for the breakup and stripping decrease of the total reaction cross section, completed the deuteron activation cross-section analysis. The overall agreement between the measured and calculated deuteron activation cross sections proves the adequacy of nuclear mechanisms suite.

Low and medium energy deuteron-induced reactions onCu63,65nuclei

The activation cross sections of (d,p), (d,2n), (d,3n), and (d,2p) reactions on 63,65Cu were measured in the energy range from 4 to 20 MeV using the stacked-foils technique. Then, following the available elastic-scattering data analysis that provided the optical potential for reaction cross sections calculations, an increased effort has been devoted to the breakup mechanism, the direct reaction stripping, and the pre-equilibrium and compound-nucleus cross section calculations, corrected for the breakup and stripping decrease of the total reaction cross section. The overall agreement between the measured and calculated deuteron activation cross sections proves the correctness of the nuclear mechanisms account, next to the simultaneous analysis of the elastic-scattering and reaction data.

Complementary optical-potential analysis of [formula omitted]-particle elastic scattering and induced reactions at low energies

A previously derived semi-microscopic analysis based on the Double Folding Model, for α -particle elastic scattering on A ∼ 100 nuclei at energies below 32 MeV, is extended to medium mass A ∼ 50 – 120 nuclei and energies from ∼13 to 50 MeV. The energy-dependent phenomenological imaginary part for this semi-microscopic optical model potential was obtained including the dispersive correction to the microscopic real potential, and used within a concurrent phenomenological analysis of the same data basis. A regional parameter set for low-energy α -particles entirely based on elastic scattering data analysis was also obtained for nuclei within the above mentioned mass and energy ranges. Then, an ultimate assessment of ( α , γ ) , ( α , n ) , and ( α , p ) reaction cross sections considered target nuclei from 45Sc to 118Sn and incident energies below ∼12 MeV. The former diffuseness of the real part of optical potential as well as the surface imaginary potential depth have been found to be responsible for the actual difficulties in the description of these data, and modified in order to obtain an optical potential which describes equally well both the low-energy elastic scattering and induced reaction data for α -particles.

Phase Problem in Nuclear Scattering Additional Constraints for the Analysis of Elastic Scattering Data

An integral equation has been derived for spin-½ particles which allows the determination of the phase of the scattering amplitude – an important prerequisite for a unique optical potential analysis. In extension of previous approaches the method takes account of the presence of non-elastic processes and of the pecularities of charged-particle scattering. In the realistic case of incomplete data with uncertainties the integral equation provides an additional constraint for the analysis of elastic scattering data.

Experimental determination of the ion-ion potential in the N = 50 target region: A tool to probe ground-state nuclear densities

Precise elastic and inelastic differential cross sections have been measured for the 16O + 88Sr , 90,92Zr, 92Mo systems at sub-barrier energies. From a coupled channel data analysis, the corresponding “experimental” bare potentials have been determined. The comparison of these potentials with those derived from double-folding theoretical calculations and the high energy (96 Mev/nucleon) elastic scattering data analysis indicate that the method is a very sensitive probe of the ground-state nuclear densities in the surface region.

58Ni +ntransmission, capture and differential elastic scattering data analysis in the resonance region

High-resolution neutron transmission, capture and differential elastic scattering measurements have been made for /sup 58/Ni-enriched targets at the Oak Ridge Electron Linear Accelerator (ORELA) from the eV to the MeV region. The three sets of data were analyzed simultaneously from 10 to 450 keV, and the transmission analysis was extended to 650 keV. For the 52 s-wave resonances observed between 10 and 650 keV, the average level spacing, D/sub 0/, and the strength function, S/sub 0/, are 12.2 +- 1.0 keV and (3.1 +- 0.6) x 10/sup -4/, respectively.

Statistical significance of phase-shift analyses for heavy-ion elastic-scattering data

It is shown that the phase-shift analysis of elastic-scattering data leads to a set of illposed, non-linear, stochastic equations. An algorithm is presented and tested which allows to find a solution, irrespective of the quality of the data. It makes use of a-priori information and determines the minimal amount of such information necessary to achieve a unique fit. The significance of the solution and its associated errors are discussed.

Analysis of Elastic-Scattering Data in the Semiclassical Approximation

The usefulness and accuracy of several approximations in the semiclassical derivation of the differential elastic scattering cross section are evaluated for the purpose of defining the best way of analyzing experimental data to obtain potential parameters.