Nuclear Temperature And Its Dependence On The Source Neutron-Proton Asymmetry Deduced Using The Albergo Thermometer

Albergo thermometers with double isotope, isotone, and isobar yield ratio pairs with one proton and/or neutron difference are investigated. Without any extra sequential decay correction, a real temperature value of 4.9 +/- 0.5 MeV is deduced from the yields of the experimentally reconstructed primary hot intermediate mass fragments (IMFs) from Zn-64 + Sn-112 collisions at 40 MeV/nucleon using the Albergo thermometer for the first time. An experimental sequential decay correction from the apparent temperatures to the real ones for 12 other reaction systems with different neutron-proton (N/Z) asymmetries in the same experiment, Zn-70, Ni-64 on Sn-112,Sn-124, Ni-58,Ni-64, Au-197, and Th-232 at 40 MeV/nucleon, is performed using an empirical correction factor approach of Tsang et al. [Phys. Rev. Lett. 78, 3836 (1997)] with the deduced 4.9-MeV temperature value. The dependence of nuclear temperature on the source N/Z asymmetry is further investigated using these deduced real source temperature values from the present 13 systems. It is found that the deduced real source temperatures at the present source N/Z range show a rather weak dependence on the source N/Z asymmetry. By comparison between our previous results and those from other independent experiments, a consistent description for the N/Z asymmetry dependence of nuclear temperature is addressed.