Nuclear Fragment Production from 720-MEV Alpha - Reactions.
Abstract
Heavy-fragment (Z 2) energy spectra from 720 MeV alpha-induced nuclear reactions on Al, Ag and Ta have been measured at 30 deg, 60 deg, 90 deg and 120 deg. The angular distributions are not well reproduced by thermodynamic evaporation models with either one or two emitting sources. The anisotropy of the low-Z fragments is, however, better described by three sources whose evenly spaced velocities and temperatures indicate that the three sources may represent a discrete approximation to an actual continuum of sources. The observed anisotropy may also be a manifestation of large contributions to the forward-angle cross sections from pre-equilibrium fragment emission. Extension of this analysis to our hydrogen-and helium-isotope data indicates that the light fragments continue the trends exhibited by the heavy-fragment data. A comparison with data from proton-induced reactions indicates that the anisotropy observed may be a manifestation of higher energy and momentum deposition in the target nucleus by alpha-particles than by protons.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 1979
- Bibcode:
- 1979PhDT........33S
- Keywords:
-
- Physics: Nuclear;
- Alpha Particles;
- Fission Products;
- Nuclear Reactions;
- Aluminum;
- Energy Spectra;
- Protons;
- Silver;
- Tantalum;
- Nuclear and High-Energy Physics