Shape effects in heavy ion (Li) elastic scattering

doi:10.1016/0370-2693(78)90341-6

Physics Letters B

Volume 78, Issue 1, 11 September 1978, Pages 36-40

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Abstract

The elastic scattering of aligned ⁶Li and ⁷Li on ⁵⁸Ni at E_cm = 12.7 MeV displays an “isotopic” effect which can be traced to the very different (mass) quadrupole moments of both isotopes. The elastic scattering of aligned ⁶Li and ⁷Li on ^12,13C at E_Li = 9 MeV displays large effects, but the angular dependence is much more complicated compared to the scattering on ⁵⁸Ni.

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Cited by (25)

Nuclear physics with polarized heavy ions
1992, Physics Reports
Polarized heavy ion beams (⁶Li, ⁷Li, ²³Na) have been in use as tools for the investigation of nuclear scattering and nuclear reactions for almost two decades. This review attempts to survey the research activities in this field with reference to nuclear structure, nuclear dynamics and reaction mechanisms. Besides reviewing the results from full quantum mechanical coupled channels analyses of data, special attention is paid to handwaving arguments and semiclassical pictures as a complementary way of obtaining a better understanding of the relevant physics.
Tidal symmetry in scattering of polarized 23Na from 208Pb
1991, Nuclear Physics, Section A
The data for differential cross sections and transverse tensor analysing powers in scattering of polarized ²³Na from ²⁰⁸Pb at 170 MeV were obtained for the ground, first and second excited states of ²³Na. The measurements were performed with the QMG/2 magnetic spectrometer at Daresbury Laboratory. The extracted data were analysed on the basis of the tidal symmetry model and the adiabatic approximation. The ground-state reorientation coupling together with two-channel and three-channel coupling schemes for ²³Na states have been attempted. Both nuclear and Coulomb terms were used in the reorientation and coupling potentials. The differential cross section and the transverse tensor analysing powers in the elastic channel are successfully described in the tidal symmetry model. However, the data in the inelastic channels are only approximately described by this model. Comparison of these results with exact coupled-channel calculations shows the implications of tidal symmetry breaking in the inelastic channels.
The polarized heavy ion source at the NSF in daresbury
1989, Nuclear Inst. and Methods in Physics Research, A
A source producing beams of polarized ⁶Li, ⁷Li and ²³Na ions has been constructed and installed at the Nuclear Structure Facility in Daresbury Laboratory. The design and performance characteristics of individual components are described together with results of a commissioning run performed with a 175 MeV tensor-polarized ²³Na beam. An on-target intensity of up to 20 pnA was observed with a tensor polarization of t₂₀ = 0.20 measured in a zero-degree polarimeter based on the ¹H(²³Na, α)²⁰Ne_g.s. reaction.
Deviations from shape-effect relations in the polarization of inelastically scattered heavy ions
1988, Nuclear Physics, Section A
Coupled-channels calculations of the collision of ¹⁶O with ¹⁵⁴Sm are performed with strong and weak absorptive potentials. In the former, the polarization tensors t_2q of inelastically scattered projectiles are seen to follow the shape-effect relations while in the latter, strong deviations from these shape relations are observed. It is shown that the adiabatic model, where the centrifugal potentials in different channels are approximated by that corresponding to the total angular momentum, J, is able to reproduce these features. The isocentrifugal approximation which uses an average orbital angular momentum fails to reproduce the deviations. Comparison between the two adiabatic models is presented. We also show how corrections for Coriolis effects may be made.
Breakup effects of 6,7li on elastic and inelastic scattering from 12C at 18-28 MeV/nucleon
1988, Nuclear Physics, Section A
The differential cross sections for elastic scattering of ^6,7Li from ¹²C and inelastic one from the lowest three excited states of ¹²C have been measured at bombarding energies of 18–28 MeV/nucleon. Theoretical analyses of the data have been performed in which consistent treatments of density distributions for the ground and excited states of both projectile and target nuclei are made in the framework of microscopic cluster models for ^6,7Li and ¹²C and projectile-target interactions are generated by the double folding of the M3Y effective nucleon-nucleon interaction. About 25% reduction of the real part of folded potentials is required both in the analyses of elastic scattering with the single-channel calculation and in those of inelastic scattering with the coupled-channel calculation including the excited states of ¹²C. This reduction can be explained as a projectile breakup effect on elastic and inelastic scattering in comparison with a coupled-discretized-continuum-channels (CDCC) calculation and an extended CDCC one which allows mutual excitations of both projectile and target nuclei for ⁶Li case, respectively. It is also seen that an effect due to the target excitation on elastic scattering is of less importance than that of the ^6,7Li projectile breakup processes even fora deformed nucleus like ¹²C. Discrepancy between the extended CDCC calculation and inelastic data for the 0⁺₂ state of ¹²C suggests a strong influence from the ¹²C → 3α breakup channels in the ⁶Li case.
Tensor interaction in heavy-ion scattering. (I). The turning-point model
1985, Nuclear Physics, Section A
The Heidelberg shape-effect model for heavy-ion tensor interactions is reformulated and generalized using the Hooton-Johnson formulation. The generalized semiclassical model (the turning-point model) predicts that the components of the tensor analysing power $T_{2q}$ have certain relations with each other for each type of tensor interaction (T_R, T_P and T_L types). The predicted relations between the $T_{2q}$ are very simple and have a direct connection with the properties of the tensor interaction at the turning point. The model predictions are satisfied in quantum-mechanical calculations for ⁷Li and ²³Na elastic scattering from ⁵⁸Ni in the Fresnel-diffraction energy region. As a consequence of this model, it becomes possible to single out effects from a T_P− or T_L-type tensor interaction in polarized heavy-ion scattering. The presence of a T_P-type tensor interaction is suggested by measured $T_{20} / T_{22}$ ratios for ⁷Li+⁵⁸Ni scattering. In the turning-point model the three types of tensor operator are not independent, and this is found to be true also in a quantum-mechanical calculation. The model also predicts relations between the components of higher-rank tensor analysing power in the presence of a higher-rank tensor interaction. The rank-3 tensor case is discussed in detail.

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^☆: Dedicated to Professor Rudolf Fleischmann, Erlangen, on the occasion of his 75th birthday.

¹: Present address: MPI für Kernphysik, Heidelberg.

²: On leave of absence from the Institute of Nuclear Research, Warsaw, Poland.

³: Present address: Fachbereich Physik der Universität Marburg.

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Physics Letters B

Abstract

References (15)

Nucl. Instr. Meth.

Nucl. Phys.

Rev. Phys. Appl.

Phys. Rev.

Phys. Rev. Lett.

Cited by (25)

Nuclear physics with polarized heavy ions

Tidal symmetry in scattering of polarized <sup>23</sup>Na from <sup>208</sup>Pb

The polarized heavy ion source at the NSF in daresbury

Deviations from shape-effect relations in the polarization of inelastically scattered heavy ions

Breakup effects of <sup>6,7</sup>li on elastic and inelastic scattering from <sup>12</sup>C at 18-28 MeV/nucleon

Tensor interaction in heavy-ion scattering. (I). The turning-point model

Shape effects in heavy ion (Li) elastic scattering☆

Abstract

Nucl. Instr. Meth.

Nucl. Phys.

Rev. Phys. Appl.

Phys. Rev.

Phys. Rev. Lett.