ONE-NUCLEON-TRANSFER REACTIONS INDUCED BY NE-20 AT 500 AND 600 MEV

The (20Ne,19Ne), (20Ne,21Ne), and (20Ne,21Na) reactions on Zr90 and Pb208 have been investigated at 500 and 600 MeV incident energies. Experimental spectra have been compared with predictions of distorted-wave Born approximation calculations. The different shapes observed for proton and neutron pickup spectra are explained quite well by the calculations. In particular, the broad peak observed at about 6.5 MeV in the (20Ne,21Ne) spectra is shown to originate from ejectile excitation in the 1d3/2, 1f7/2, and 2p3/2 orbitals. An important component of the (20Ne,19Ne) cross section is due to three-body processes, such as the elastic breakup of Ne20 into Ne19 and one neutron. In addition, bumps are observed at about 1.5 and 10 MeV excitation energy in Pb209 and 2.5 and 14 MeV in Zr91. The low energy peaks are shown to originate mainly from neutron transfer to high spin orbitals, i.e., 1i11/2 and 1j15/2 in Pb209 and 1g7/2 and 1h11/2 in Zr91. Because of the selectivity of the (20Ne, Ne19) reaction for large angular momentum transfer, it is proposed that the structures observed at 14 MeV in Zr91 and 10 MeV Pb209 are due to a neutron transfer to high spin orbitals, such as 1i13/2 and 1k17/2 in Zr91 and Pb209, respectively. © 1990 The American Physical Society.