Dynamical emission and isotope thermometry

Ratios of the populations of ground and excited states of He-4, Li-5, and Be-8 and double ratios constructed from the yields He-3,He-4, Li-6,Li-7,Li-8, C-11,C-12,C-13 isotopes were measured for central Kr+Nb collisions at E/A = 35, 70, 100, and 120 MeV. These ratios were analyzed to estimate an apparent temperature for emission. Consistent and approximately constant apparent temperatures were obtained from the excited states of He-4, Li-5, and Be-8 nuclei and from thermometers based upon the yields of carbon isotopes. In contrast, apparent temperatures obtained from thermometers based upon the ratios using helium isotopes increase monotonically with incident energy.