In the framework of the Skyrme-Hartree-Fock approach with 36 sets of the TI J parameterizations,the tensor force effect on the evolution of the single-proton states in the calcium isotopes is systematically investigated.It is shown that the single-proton states with higher angular momenta are influenced significantly by the tensor force and the trend in the evolution of somesingle-particle energy differences with the mass number of the isotopes depends sensitively on a parameter βT associated with the intensity of the tensor force.To understand this phenomenon,we analyze the spin-orbit potentials and the radial wave functions of relevant single-proton orbits in detail.In addition,it is found that some TI J interactions could cause the 2s1/21d3/2 energy level inversion in 48Ca.
The frequency distribution of different ingredients in-ray spectra,e.g.,photo-peak,fluctuations of counts and Compton region,is separately analyzed.After wavelet transform of-ray spectra,the wavelet coefficients of a photo-peak increase with transforming scales and these coefficients show direct proportion with intensity of peak at determinate scale.A novel algorithm based on wavelet transform is proposed and studied.The results indicate that most of the photo-peaks in multi-spectra can be determined accurately,the-rays energy and intensity of the peak can also be determined.This method has the prospect of being applied in on-line multi-spectra analysis in such fields as radioprotection and nuclear safety monitoring.
将基于组合方法的角动量投影的位能曲面群用于研究铅同位素原子核^(190,192)Pb的超形变转动带。位能曲面群计算中采用了Gogny D1S以及Skyrme Sk P SLy4三种相互作用。如用Gogny D1S相互作用,^(190)Pb原子核没有明显的超形变转动带,而^(192)Pb原子核有非常显著的超形变转动带。用W.K.B.方法计算了^(192)Pb原子核的超形变带穿透宽度。该穿透宽度很大与用GW模型(Nucl.Phys.A 660(1999)197)分析实验数据给出的结果相近。在Gogny D1S相互作用情形下,就角动量投影对位能曲面群的影响作了讨论,发现角动量投影压低了分隔超形变转动带与正常形变转动带之间的位垒。还用Skyrme Sk P和SLy4相互作用计算了角动量投影的位能曲面群,发现位垒明显高于Gogny D1S相互作用给出的位垒。在Skyrme相互作用情形下,^(192)Pb原子核的超形变带穿透宽度明显小于Gogny相互作用给出的宽度,但是较SB方法 (Phys.Rev.C,60(1999)051305)分析实验数据得到的结果高出几个数量级。于是,对SB方法提出了质疑,因为它给出了极其微小的传播宽度。
The mass-dependent symmetry energy coefficients asym(A) has been extracted by analysing the heavy nuclear mass differences reducing the uncertainties as far as possible in our previous work.Taking advantage of the obtained symmetry energy coefficient asym(A) and the density profiles obtained by switching off the Coulomb interaction in208 Pb,we calculated the slope parameter L0.11 of the symmetry energy at the density of 0.11 fm-3.The calculated L0.11 ranges from 40.5 Me V to 60.3 Me V.The slope parameter L0.11 of the symmetry energy at the density of 0.11 fm-3is also calculated directly with Skyrme interactions for nuclear matter and is found to have a fine linear relation with the neutron skin thickness of208 Pb,which is the difference of the neutron and proton rms radii of the nucleus.With the linear relation the neutron skin thickness Rn pof208 Pb is predicted to be 0.15–0.21 fm.
