超重的物理原理及对人体的影响

本文介绍了超得的物理原理及对人体所造成的影响和相关的防护措施。     

超重核合成的同位素依赖探讨

利用二参量Smoluchowski方程计算了54Fe+204Pb,56Fe+206Pb,58Fe+208Pb冷熔合和32,34,36S+238U热熔合的复合核形成截面和蒸发残余截面, 结果清楚地显示出超重核合成截面随同位素的变化。 由于较低的入射道库仑位垒、 较低的不对称裂变谷中的条件鞍点和较小的中子分离能, 一般地说, 丰中子同位素的超重核形成截面明显增强。 The cross sections of the compound nucleus formation and e vaporation residue for the 54Fe+204Pb, 56Fe+206Pb, 58Fe+208Pb cold fusion and 32,34, 36S+238U hot fusion have been calculated by using a two parameter Smoluchowski equation. Our results clearly show the isotope dependence of superheavy nucleus production. The formation cross sections of the neutron rich isotope are, generally speaking, obviously enhanced due to the lower Coloumb barrier , lower height of the conditional saddle point, and smaller neutron separation energy.     

超重核研究谱仪的RFQ冷却聚束器RFQ1L

介绍了超重核研究谱仪中RFQ冷却聚束器RFQ1L的结构和运用SIMION程序对离子的冷却、聚束、引出和撇气过程的模拟情况。 模拟显示: 通过仔细选择工作点就完全可以把经过充气反冲质量分离器分离后的低品质束流转化为斑点小、发射度小和能量单一的高品质束流, 为紧接其后的磁铁和激光高效率分析提供条件。The structure and the simulation results about the cooling,bunching,extraction and skimming of the RFQ cooler and buncher RFQ1L, which is an important part of the being built super heavy nuclide research spectrometer, have been introduced. It shows that, by careful choice of its working point, we can obtain an ion beam with small beam spot, small emittance and mono energy, which can satisfy the requirements of the successive analyses by dipole and laser with high efficiencies.     

超重核α衰变寿命的理论研究

建立了计算球形核α衰变寿命的新模型——密度依赖的结团模型(DDCM)。在此基础上,通过引入子核的形变自由度,发展了形变的密度依赖的结团模型, 编写了形变的DDCM程序。并系统计算了Z=106—110的超重核α衰变寿命。通过与已有的实验数据的对比分析, 发现理论结果和实验数据符合得很好,验证了DDCM在超重核区域的适用性。We proposed a deformed version of density dependent cluster model (DDCM) by including nuclear deformation of the daughter nucleus. A systematic calculation of α decay half lives of superheavy nuclei (Z=106—110) is carried out by the deformed DDCM. The good agreement between theory and data is obtained. It is shown that the deformed DDCM works well in the superheavy mass region.     

偶-偶超重核基态性质的理论研究

在形变的相对论平均场模型下采用NL Z2,TMA两套参数对一些偶 偶核基态性质进行了系统的计算,并将理论计算的结合能、α衰变能与已知的实验数据进行了对比分析.结果发现两方面的数据能够比较好地吻合,从而验证了相对论平均场模型对超重核研究是可行的.同时在计算中给出了未知核素基态性质的计算结果,可供以后在理论或实验上研究超重核时参考. The ground state properties of the even even nuclei with proton number Z=94-104 have been systematically calculated in the deformed relativistic mean field (RMF) theory with two sets of force parameters, TMA and NL Z2. Comparing the calculated binding energies and alpha decay energys with the experimental ones, it is found that theoretical results are in good agreement with experimental data. The reliability of the RMF model for even even superheavy nuclei has been tested by this comparison...     

超重核稳定岛渐露峥嵘：从元素114的发现谈起

光明日报1999年1月26日载新华社莫斯科1月24日电,据俄罗斯《独立报》23日报道,由俄美科学家小组去年底在美国加州劳伦斯·利弗莫尔国家实验室共同发现元素114,新元素的原子量为289,它填补了化学元素周期表上一个空白。找到114号元素是一项极为重要的实验,因为其寿命长达30秒以上,是迄今为止最长寿的超重元素。全世界的各大报纸都加以报道,美国科学促进会发了专稿。消息传来,使人振奋,因为广大化学教育工作者、大中学生莫不关心化学元素周期表的结尾？超重核稳定岛是否存在？那里有什么奥秘？这是一个十分令人神往的诱人目标,真可…     

超重核合成的新进展

介绍了在充气分离器上用２４４Ｐｕ（４８ Ｃａ,３ｎ）２８９１１４和２０８ Ｐｂ（８４ Ｋｒ,ｎ）２９３１１８反应分别合成超重核２８９１１４和２９３１１８的新发现． Introduction of the first synthesis of new superheavy nuclei 289114 and 293118 in reactions of 48Ca+244 Pu and 86 Kr+ 208 Pb.     

Oblate Superdeformed High-K States in Superheavy Nuclei

Configuration-constrained calculations of potential -energy surfaces for292122 show the occurrence of multiquasiparticle high-K isomeric state at oblate superdeformation. Such state could play a unique role in superheavy nuclei,with possible long life time from enhanced difculty in fission due to additional barrier at oblate deformation, retardation in α decay due to unpaired nucleons, and hindrance in γ-ray transition due to K forbiddenness.     

沙漏超重和失重的数字化实验研究

沙漏是一种常见的计时与装饰仪器.在沙子下落过程中,沙漏受力情况会发生复杂的变化.这里结合牛顿运动定律完整地分析沙子处于沙漏上端静止、下落、空中下降、撞击、下端静止等5个阶段的运动情况.我们通过自制简易装置,并利用Vernier LabPro传感器较好地观测到沙子下落的整个阶段,而且所测数据与理论分析相一致.     

α-decay half-lives of superheavy nuclei and general predictions

The generalized liquid drop model （GLDM） and the cluster model have been employed to calculate the α-decay half-lives of superheavy nuclei （SHN） using the experimental α-decay Q values. The results of the cluster model are slightly poorer than those from the GLDM if experimental Q values are used. The prediction powers of these two models with theoretical Q values from Audi et al. （QAudi） and Muntian et al. （QM） have been tested to find that the cluster model with QAudi and QM could provide reliable results for Z 〉 112 but the GLDM with QAudi for Z 112. The half-lives of some still unknown nuclei are predicted by these two models and these results may be useful for future experimental assignment and identification.