核耗散强度对超重核蒸发剩余截面的影响

The influence of nuclear dissipation intensity on the evaporation residue cross section of superheavy nuclei

尽管目前利用熔合蒸发反应合成超重核的研究陷入停顿,但该反应机制仍是实验室合成新核素的主要方法.为了研究核耗散强度对超重核素合成截面的影响,通过冻结能级密度参数及其在鞍点和基态处的比值,对超重元素Cn、Fl和Lv的7个反应进行了数值计算.计算结果表明重现实验数据所需核耗散强度随超重余核质量数的减小而逐渐减弱.此外,相比于对282,283Cn和292,293Lv的模拟,要重现新质子幻数Z=114对应的超重复合核287,288,289Fl的实验数据则需要增强核耗散强度.上述规律为获取超重核的结构信息提供了一种潜在的核反应学方法.

Although the synthesis of superheavy nuclei by fusion-evaporation reaction plateaus for ten years,it is still a main formation method in the laboratory.In order to investigate the effect of nuclear dissipation intensity on the evaporation residue cross section of superheavy nuclei,we set the following input paramters as constant,i.e.the level density parameters of compound nuclei and the radio at the saddle point and the ground state,and then to calculate the seven reactions which to produce the superheavy elements,namely Cn,Fl and Lv,respectively.The results show that the nuclear dissipation strength which to reproduce the experimental data weakens with the decrease of mass numbers of superheavy residue nuclei.In addition,compared with the simulations for 282,283Cn and 292,293Lv,it is necessary to enhance the strength of nuclear dissipation of the superheavy compound nuclei in order to reproduce the experimental data for Fl isotopes,namely 287,288,289Fl,which with the next magic number Z=114 predicted by different theories.The above results provide a potential nuclear reaction method to get the nuclear structural information of superheavy nuclei.