Nuclear phase transition studied with antisymmetrized molecular dynamics with momentum fluctuations: A microscopic analysis without model assumption

Liquid-gas phase transition of finite nucleus is studied by means of microscopic reaction theory antisymmetrized molecular dynamics with momentum fluctuations. By calculating the time development of hot system in a potential well, thermodynamic variables, such as temperature and pressure and their relationship to the excitation energy of the system, are obtained. We see clearly the existence of three regions in calculated caloric curve, namely, liquid-dominant, plateau, and gas regions. The transition from liquid-dominant phase to gas phase begins with the cracking of hot liquid nucleus and disintegration into fragments. The property of plateau region strongly depends on the pressure of the system. The gas phase is well reproduced by van der Waals’ equation.