利用最近发展起来的两步模型分析重离子核反应^48Ca+^254Es的熔合过程。在这个模型中,熔合过程被分为前后独立的两个过程,即粘连过程和形成过程。本研究组计算了对应的粘连概率和形成概率,并结合适用于蒸发过程的统计蒸发模型,计算了该反应合成119号超重元素的剩余截面,即当Elab=250.2MeV时,得到最大剩余截面为0.7pb。
Two-step model is adopted to analyze the fusion process of heavy-ion reaction 48Ca +254 Es. Based on this model, the fusion process is divided into two consecutive steps, i.e., the sticking step and the formation step, and corresponding sticking probability and formation probability are calculated. Combining the statistical evaporation model for the evaporation stage, the maximum evaporation residue cross section for reaction 48Ca +254 Es is 0.7 pb at 4n, Elab = 250.2 MeV. Key words: superheavy nuclei; hot fusion; sticking probability; formation probability; residue cross section