Systematics of the 14N + 159Tb reaction between 6 and 22 MeV/u : (I). Inclusive data

Abstract

As part of an investigation of the 14N + 159Tb reaction in the energy range between 6 and 22 MeV/u inclusive angular distributions and energy spectra for isotopes with Z ⩽ 9 have been measured at bombarding energies of 92, 236 and 309 MeV. For completeness data at 112, 140 and 168 MeV previously obtained at this laboratory are included. Over the whole energy range projectilelike fragments (PLF's) with Z ⩾ 3 are observed to be mainly produced in a quasi-elastic process, while only a small fraction of the PLF's (<10% for Z PLF ≧ 5) appear to originate from deep-inelastic reaction channels. The mass flow is almost exclusively in the direction of the target. The angle integrated inclusive cross sections for the formation of the different PLF's rise first and then stay rather constant as a function of bombarding energy. The cross sections for light particles with Z ⩽ 2 are separated into components due to evaporation and to non-evaporative processes, respectively. Both components are observed to increase in magnitude with increasing bombarding energy over the whole energy range. The present data will serve as the basis for a more detailed study of the reaction with the help of semi-exclusive measurements, to be presented in forthcoming publications.