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,line...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.展开更多
基金The project supported by the National Natural Science Foundation of China
文摘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.
