R. Böttger

Elastic scattering of vector polarized 7Li on 58Ni

The elastic scattering of 6Li from 4He has been subject of recent investigations1,2). In all cases the observed angular distributions of the differential cross section show pronounced structures at intermediate and backward angles. These structures have been interpreted1,2) as due to the elastic transfer of a deuteron between the two 4He-cores. In order to obtain a more detailed information on the reaction mechanism a study of the vector analyzing power for this reaction had been started using the polarized 6Li beam of the Heidelberg EN-tandem3). The experiment has been performed at 22.8 MeV beam energy and scattering angles of 35 < θcm < 150°. As 4He target a gas cell was used which was specifically constructed to allow for measurements of the left-right asymmetry. The entrance and exit windows consisted of Havar-foils of 2.1 mg/cm2. The target has been operated at pressures around 500 torr 4He corresponding to an effective target thickness between 30 and 80 μg/cm2. Taking into account the energy loss in the entrance foil and in the gas target the beam energy at the active volume of the gas cell is Elab ≈ 21.3 MeV. The scattered 6Li- and the rescattered 4He-nuclei have been detected with ΔE-E telescopes. Relative and absolute normalization of the data has been obtained by measuring the Rutherford scattering of 6Li from a 3.6% Kr-admixture to the 4He-gas.

Investigation of the 58Ni(7Li, 6Li)59Ni reaction with vector polarized 7Li

Abstract Angular distributions of the cross section and of the vector analyzing power for the 58Ni(7 Li , 6Li)59Ni reaction leading to several groups of levels in the final nucleus have been measured at ELi = 20.3 MeV. The observed Q-value dependence of the vector analyzing power can to a large extent be attributed to a kinematical effect caused by the polarization of the orbital angular momentum of the transferred neutron in 7Li.

The influence of the spectroscopic deformation of Li-isotopes on their interaction with51V

The energy dependence of the total reaction cross sectionσr and its tensor analyzing powerT20r was measured for the7Li−51V interaction in the energy rangeELi=10–20 MeV using two different experimental methods. Reaction residues were observed directly by their characteristicγ-emission, and the elastic scattering of7Li from51V was investigated. Additionally, the elastic scattering of6Li from51V was measured at 9.8, 12 and 14 MeV. The tensor analyzing power data can be interpreted as being caused by the spectroscopic mass deformation of the Li-ions. The energy dependence of σr andT20r above the Coulomb barrier can be described in terms of the classical sharp-cutoff model.

Determination of the alignment of a 7Li beam by means of the Doppler-shift method

Abstract It is demonstrated that an analysis of the shape of the Doppler-broadened 0.478 Mev γ-line from 7Li Coulomb excitation allows the determination of the alignment of a 7Li beam, provided the alignment of the beam can be switched on and off.

Shape effects in the 7Li−51V reaction cross section

The energy dependence of the reaction cross section and its tensor analyzing power Treac20 has been measured for the 7Li‐51V interaction by two different methods. The tensor analyzing power data can be interpreted as caused entirely by the static deformation of the 7Li‐ions.

Polarization monitors for polarized heavy ions

Reactions of various spin types are discussed in respect to their use as calibrator and monitor for polarized heavy ion beams. The first results obtained with a ‘‘Doppler‐shift’’ polarimeter are also presented.

Analysis of elastic scattering of polarized 7Li on 58Ni within the diffraction model

For the 7Li‐58Ni elastic scattering angular distributions of the differential cross section and of the vector analyzing power at ELi=20.3 MeV and of the tensor analyzing power TT20 at ELi=18.0, 20.3 and 22.0 MeV are analyzed within the diffraction model. The data for TT20 have been measured for this purpose.

Production of vector polarized nuclei by 7LI beams

First results on the production of polarized 8Li and 12B by vector polarized 7LI beams are reported. The polarization transferred to the residual nuclei was measured by detecting the resulting β‐asymmetries.

Elastic and inelastic scattering of vector polarized 7Li on 58Ni

Elastic and inelastic (projectile excitation) scattering of vector polarized 7Li on 58Ni has been investigated at ELi=20.3 MeV. The vector analyzing power for elastic scattering surprisingly turns out to be negative.

The elastic scattering of tensor polarized 7Li on 58Ni

Data for the elastic scattering of tensor polarized 7Li on 58Ni at ELi=20.3 MeV can be described with an optical potential which includes a complex TR tensor interaction. The strength of the tensor term is determined by the parameter of the central potential and by the deformation of the 7Li nucleus.