²³⁹Pu & ²⁴¹Am Decay Data Evaluation And Study Of Ground Band In A～160 Even-Even Nuclei

This article includes two major parts. The first one is mainly about the decay data evaluation. General phenomena, law, and elementary theory about nuclear radioactive decay introduced in this part. Study of radioactive decay established the law of statistical decay, which is an important characteristic of motion of matter in microworld. Since 1940s, nuclear physics has entered a new era of rapid development and has become the very important front field of the sciences research. Through a large number of scientific experiments, people have a better understanding on the basic structure of nuclei and change regularity. For the nature of the ground states and lower excited states in stable nuclides or longer life of radionuclides, many experimental data were reported, and various nuclear models were established. The continuous in-depth study of radioactive decay supplies powers for nuclear technology and some cross-discipline development. In recent years, nuclear technology is a very important area of research in the modern science, and maintains vitality. Nuclear technology not only is vital to science, but also in the field of high-tech and cross-disciplinary research plays an important role. The appliance of the applied nuclear technology has become more and more popular in industry and daily life. The nuclear technology application usually requires a variety of nuclear data, and nuclear decay data is essential in a considerable number of nuclear technology applications. Present work mainly on the ²³⁹Pu and ²⁴¹Am decay data evaluation. We mainly collected the experimental data of the half-life, Q value,α-ray energy,α-ray absolute intensity,γ-ray energy and absolute intensity,γ-ray intensity normalized factor in the past 60 years to evaluate the new data, and the old data files and the new data were compared. The half-life value of ²³⁹Pu recommended has an improved accuracy in the article than in NDS(2003BR12) and this work found a 1981BRAA measurement data which is not included in the former evaluation; Moreα-ray energy recommended in the article were calculated by Q values and Energy level values, and these values are agreement with the values suggested in NDS(2003BR12) ; Otherα-ray energy values were recommend by considering the 1993GA28, 1996VI07, 1996BU50 data, and the recommended values were significantly different from NDS(2003BR12) recommend values; The values of theγ-ray energy andγ-ray absolute intensity in line with the NDS(2003BR12); In addition, we found 1981AhZV measurement data on the evaluation ofγ-ray absolute intensity in ²³⁹Pu, which is not incorporated in previous evaluations. The value of half-life of ²⁴¹Am suggested in the present work slightly different from that recommended in NDS(2005MA88) ; The values ofα-ray energy andγ-ray absolute intensity with lager differences between percent work and NDS(2006BA41); The values of theγ-ray energy suggested in this article are in excellent agreement with the values suggested in NDS(2006BA41)The second part briefly introduced the exponential dependence of the nuclear moment of inertia on pairing correlation and studied moment of inertial in A～160 nuclei by the model. The experimental value of J for the nuclear ground state lies between the rigid-body and irrotational flow limits, and it depends strongly on the nuclear pairing correlations. The moment of inertia value was significantly less than the rigid-body value due to pairing correlation. But pairing correlation destroyed completely at a higher frequency of rotation, and the value of J in the ground rotational band increases for increasing spin. In this case, the pairing-gap parameter will tend to zero, then the value of the moment of inertia will tend to rigid-body values. We study the ground rotational band in A～160 even-even nuclei, and J₀ was extrapolated. If J₀ can be considered equivalent to the rigid body moment of inertia, it would be used to discuss the nuclear deformation. The experimental values extrapolated generally less than the theoretical values of rigid body moment of inertia, and this difference is analyzed and discussed in the paper. I_c obtained is also too small to consistent with the physical meaning.