摘要
Hot nuclei produced in the reactions of 25 MeV/u<sup>40</sup>Ar with <sup>209</sup>Bi and<sup>Na1</sup>Ag are studied.Theinitial properties of these nuclei :excitation energies,linear momentum transfer and temperatures are char-acterized through the measurements of folding angle of fission fragments,light charged particle energyspectra and intermediate mass fragments.Nuclei with excitation energies as high as～600 MeV and tem-peratures as high as～6 MeV are produced.The spectra of alpha particles detected in coincidence with fis-sion fragments in the case of different average linear momentum transfer are analyzed and the initial tem-peratures of the hot nuclei are determined.A saturation（or limiting）temperature near 6 MeV is foundfor alpha emission from medium mass nuclei having excitation energies higher than 3 MeV/u.This resultprovides evidence for a soft nuclear equation of state at thee high excitation energies and is consistentwith predictions of statistic multifragmentation model calculations.
Hot nuclei produced in the reactions of 25 MeV/u<sup>40</sup>Ar with <sup>209</sup>Bi and<sup>Na1</sup>Ag are studied.The initial properties of these nuclei :excitation energies,linear momentum transfer and temperatures are char- acterized through the measurements of folding angle of fission fragments,light charged particle energy spectra and intermediate mass fragments.Nuclei with excitation energies as high as～600 MeV and tem- peratures as high as～6 MeV are produced.The spectra of alpha particles detected in coincidence with fis- sion fragments in the case of different average linear momentum transfer are analyzed and the initial tem- peratures of the hot nuclei are determined.A saturation（or limiting）temperature near 6 MeV is found for alpha emission from medium mass nuclei having excitation energies higher than 3 MeV/u.This result provides evidence for a soft nuclear equation of state at thee high excitation energies and is consistent with predictions of statistic multifragmentation model calculations.
作者
Wu, Enjiu
Jing, Genming
Zheng, Jiwen
Yin, Shuzhi
Tan, Jilian
Zhang, Chun
Jin, Weiyang
Song, Mintao
Li, Zhuyu
Wu, Heyu
Wang, Shufang
He, Zhiyong
Jiang, Dongxing
Qian, Xing
基金
The project supported by the National Natural Science Foundation of China
