摘要
用正则系综蒙特卡罗摸拟方法研究余核破碎问题时,若对碎块位置的平均采取近似的办法,就可以得到余核(RT)系统破碎时的状态方程.本文用数值方法计算了该状态方程,得到了广义压强(P)-体积(V_(RT))平面上的等温曲线;它与Van der Waals气体相应等温线有类似之处;相变温度就应该对应于只有一特点的等温曲线的温度.本文又指出,描写破碎问题的统计模型中的两个参数,即破碎温度(T)和破碎体积(V_(RT)),在一定的变化范围内都能符合碎块质量分布数据.也就是说,(T,V_(RT))对不是唯一的.一定温度下与实验符合最好的一对参数,就是相应等温线的两相共存区内压强的极大点.
Following the method developed by the authors, recently, the equation of state of hot nuclei (^(238)U in concrete) before break-up was investigated numerically. The isotherms are drawn in the plan of the general pressure P versus volume V_(RT). They are similar to those of Van der Waals gas. The critical temperature of phase transition should correspond to the isotherm with one turning point only. It turns out that the data of mass yield distribution can be reproduced by many pairs of parameters T and Vm (freeze-out temperature and freezeout volume) varying in certain range. For each isotherm (each T), the data are always best reproduced by the value of V_(rt) located at the maximum general pressure within two phases coexistence region.
出处
《高能物理与核物理》
CSCD
北大核心
1989年第8期706-713,共8页
High Energy Physics and Nuclear Physics
基金
国家自然科学基金
