N. Marquardt

Nucleon exchange in the low-energy scattering of α-particles on 6Li and 7Li

Abstract Excitation functions for the elastic scattering of α-particles on 6 Li and 7 Li were measured between 2.5 and 4.5 MeV. Angular distributions have been measured at 3.0 and 4.0 MeV for 6 Li and 3.6 MeV for 7 Li, at energies well separated from compound nucleus resonances. The increase of the differential cross section above the Rutherford scattering could be well described by the exchange of a deuteron for 6 Li using the methods of molecular wave functions. The extracted spectroscopic amplitude for the deuteron is 1.0, which agrees well with the values of the cluster model. For 7 Li no analysis was performed. This case is more complicated, the transfer of the triton in a 3 2 − configuration involving an l = 2 transfer and due to the presence of a strong inelastic transition to the 1 2 − state in 7 Li.

Nucleon exchange in scattering of carbon isotopes

Abstract The elastic scattering of 12 C on 13 C and 14 C, of 13 C on 14 C has been measured in the vicinity of the Coulomb barrier. The structure of the angular distributions is consistently described using the method of molecular wave functions which takes into account the exchange of the valence particles.

Effect of the core spin on the exchange of nucleons in the scattering of 14N on 12C and 13C

Abstract The elastic scattering of 14 N on 12 C and 13 C has been measured at the same CM energy (9.8 MeV). The oscillatory structures observed in the two angular distributions are out of phase. This fact is well reproduced by an analysis using molecular wave functions which takes into account the spin of the target nuclei.

Elastic scattering of15N on19F,19F on18O and19F on16O at low energies and elastic transfer

Angular distributions of the elastic scattering in the range of 30–160 ° θcm have been measured for the systems15N+19F,19F+16O and19F+18O at three energies, the highest being approximately 4 MeV above the Coulomb barrier. The large differences observed in the structure of the angular distributions at large angles are discussed considering elastic transfer, and the angular momentum balance for the possible direct surface reactions. The analysis yields a consistent description of the data in terms of elastic transfer.

Evidence for a direct eight-nucleon transfer reaction and multiparticle excitation of 20Ne

Abstract Results from a study of the 12 C( 14 N, 6 Li) 20 Ne reaction are presented which give evidence that the reaction proceeds via the direct transfer of eight nucleons. Comparison of the spectra of the emitted 6 Li particles to spectra from four-nucleon transfer reactions also leading to states in 20 Ne show clear differences in the excitation of the various rotational bands. The selectivity of the ( 14 N, 6 Li) reaction provides a new probe for investigating multiparticle-excited states and states having high angular momenta.