Abstract
Fragment distributions resulting from collisions at an incident energy of are studied. From the measured fragment and neutron distributions the mass and the excitation energy of the decaying prefragments were determined. A temperature scale was derived from observed yield ratios of He and Li isotopes. The relation between this isotope temperature and the excitation energy of the system exhibits a behavior which is expected for a phase transition. The nuclear vapor regime takes over at an excitation energy of 10 MeV per nucleon, a temperature of 5 MeV, and may be characterized by a density of 0.15–0.3 normal nuclear density.
- Received 31 January 1995
DOI:https://doi.org/10.1103/PhysRevLett.75.1040
©1995 American Physical Society