Temperature measurements in central collisions

✍ Scribed by M.B. Tsang; H.F. Xi

• Book ID: 104334107
• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 228 KB
• Volume: 654
• Category: Article
• ISSN: 0375-9474
• DOI: 10.1016/s0375-9474(00)88554-1

✦ Synopsis

At incident energies in excess of about E/A=50 MeV, a rapid collective expansion of the combined system may occur during the later stages of a central collision between heavy nuclei. The emission of the observed particle species occurs after initial overlap and before the density of the system passes below about 0.1Po, corresponding to an expansion rate dependent on the total emission time which is less than 100 fm/c. The short emission times motivate the description of such collisions via dynamical models or via statistical models which assume equilibrium at a single breakup density and temperature. This latter class of models includes bulk multifragmentation models such as the Statistical Multifragmentation Model (SMM) which displays a phase transition in sub-saturation density [1]. Calculations predict enhanced heat capacities for finite nuclear systems at temperatures of the order of 4-6 MeV due to the transformation from the Fermi liquid which can be found in the interior of large nuclei in their ground and low excited states to a gas phase consisting of free nucleons and light clusters.