# Nuclear Science and Techniques

《核技术》(英文版) ISSN 1001-8042 CN 31-1559/TL     2019 Impact factor 1.556

Nuclear Science and Techniques ›› 2013, Vol. 24 ›› Issue (5): 050501

• Special Section on International Workshop on Nuclear Dynamics in Heavy-Ion Reaction (IWND2012) •

### IMF production and symmetry energy in heavy ion collisions near Fermi energy

WADA Roy1,*  HUANG Meirong1  LIN Weiping1,2  LIU Xingquan1,2 #br# ZHAO Minghui1,2  CHEN Zhiqiang1

1. 1Institute of Modern Physics, Chinese Academy of Science, Lanzhou 730000, China 2University of Chinese Academy of Sciences, Beijing 100049, China
• Received:2013-06-27
• Contact: WADA Roy E-mail:wada@comp.tamu.edu
• Supported by:

Supported by National Natural Science Foundation of China (NSFC) Projects (No.11075189), “100 Persons Project (Nos. 0910020BR0 and Y010110BR0)” and “ADS project 302” of the Chinese Academy of Sciences (No. Y103010ADS). Also supported by U.S. Department of Energy (Grant No. DE-FG03-93ER40773) and Robert A. Welch Foundation (Grant A0330).

WADA Roy, HUANG Meirong, LIN Weiping, LIU Xingquan, ZHAO Minghui, CHEN Zhiqiang. IMF production and symmetry energy in heavy ion collisions near Fermi energy.Nuclear Science and Techniques, 2013, 24(5): 050501

Abstract:

The symmetry energy at the time of the production of intermediate mass fragments (IMFs) is studied using experimentally observed IMF multiplicities combined with quantum statistical model calculations (QSM of Hahn and Stöcker). The ratios of difference in chemical potentials between neutrons and protons relative to the temperature,  , and the double ratio temperature, T, were extracted experimentally in the reactions of 64,70Zn, 64Ni+58,64Ni, 112,124Sn, 197Au, 232Th at 40A MeV. The extracted   scales linearly with δNN, where δNN is the asymmetry parameter, (NZ)/A, of the emitting source and   was derived. The experimentally extracted   and the double ratio temperatures are compared with those from the QSM calculations. The temperatures, T, and densities, ρ, extracted from the   values agreed with those from the double ratio thermometer which used the yield ratios of d, t, h and α particles. However the two analyses of the differential chemical potential analysis and the initial temperature analysis end up almost identical relation between T and ρ. T=5.25±0.75 MeV is evaluated from the   analysis, but no density determination was possible. From the extracted T value, the symmetry energy coefficient Esym=14.6±3.5 MeV is determined for the emitting source of T=5.25±0.75 MeV.