Study of thermometers for measuring a microcanonical phase transition in nuclear fragmentation

The aim of this theoretical work is to study how the thermodynamic temperat ure is related to the known thermometers for nuclei especially in view of s tudying the microcanonical phase transition. It is known within the MMMC-mo del that the "S-shape" of the caloric equation of state e*(T) is the signal of a phase transition in a system with conserved energy. We find that this signal could be seen in the experimentally accessible slope temperatures T -slope for different particle types and also in the isotopic temperatures T He-Li. The calculated isotopic temperatures TH-He weaker correlated to the shape of the thermodynamic temperature and therefore are less favorable to study the signal of a microcanonical phase transition, We also show that th e signal is very sensitive to variations in mass of the source. (C) 1999 El sevier Science B.V. All rights reserved.