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1.
The approximate angular momentum projected Hartree-Fock(PDHF)method is used to some odd-A nuclei in the fp shell:47Ti,47V,47Cr,49Cr.Their energy spectra are calculated and compared with the experimental data.The results are fairly satisfactory.In addition,the characteristics of those spectra are analyzed with the particle-rotor model.It is found that those spectra possess the properties of the no alignment limit Spectra. 相似文献
2.
Han Yong 《中国物理C(英文版)》1998,22(11):1020-1028
Taking the modified surface delta interaction (MSDI) and using a spherical shell model basis set, we carry out the deformed Hartree-Fock (HF) calculation for the even-even nuclei 46Ti and 48Cr in the fp shell, and construct the deformed HF intrinsic states which are the Slater determinants from the HF single-particle states.The angular momentum projection program is then carried out and the reasonable results are obtained. 相似文献
3.
APPLICATIONS OF THE MODIFIED SURFACE DELTA INTERACTION IN THE ANGULAR MOMENTUM PROJECTION DEFORMED HAREE-FOCK METHOD 下载免费PDF全文
LIAO Ji-Zhi 《中国物理C(英文版)》1989,13(4):357-361
In this paper a modified surface delta interaction with an angular momentum correction term is proposed.By using this interaction the deformed Hartree-Fock and the approximate angular momentum projection calculations are performed for even-even nuclei in mass region A=56—74.The single particle energy spectra of the ground state configurations obtained are more reasonable than that calculated with KB matrix elements.The agreement of the calculated binding energies and projection energy spectra with experimental ones is fairly good. 相似文献
4.
LIAO Jizhi 《理论物理通讯》1999,31(3):415-420
The energy staggering in γ-or quasi γ-band of γ-soft even-even nuclei is studied with the approximate angular moment um projection of the deformed Hartree-Fock (DHF) states. In the calculations of DHF states the modified surface &interaction matrix elements are used. It is found that in the K = 2 band produced by the angular momentum projection of DHF state the energy staggering appears only in certain conditions. Some points concerning with the angular momentum projection of K = 2 DHF states are discussed. The energy spectra of nuclei 74Se and 76Kr are calculated and compared with the experimental data, which show the staggering pattern of γ-soft rotor, the coincidence between them are fairly good. 相似文献
5.
Application of the Modified BUU Model to Reaction Induced by 16O on 197An at 20MeV≤E/u≤180 MeV:Dependence of the Angalar and Linear Momentum Transfer on Impact Parameter and Energy 下载免费PDF全文
The angular and linar momentum transfered to target residue on 20 to 180MeV/u 16O+197Au system are calculated with BUU(Boltzmann-Uehling-Uhlenbeck) model in which the angular momentum conservation is added.The dependence of angular and linar momentum on impact parameter and incident energy is discussed.The deviations between calculated values of(1mt) and those from viola system are compared.The results of the simulations suggest that the saturation of angular momentum transfer with incident energy increase mainly comes from the loss of capture ability of the target on projectile. 相似文献
6.
A variational calculation after an approximate angular momentum projection for 158Er indicates that the anomalous behaviour of the energy spacings of high spin states may be due to centrifugal stretching — an increase in deformation accompanied by a decrease in pairing correlations. 相似文献
7.
A SEMI-CLASSICAL ANALYSIS ON THE REACTION 12C+209Bi AT BOMBARDING ENERGIES SLIGHTLY ABOVE THE COULOMB BARRIER 下载免费PDF全文
For reactions induced by light heavy ion such as 12C, at bombarding energy slightly above the coulomb barrier, using semi-classical theory, neglecting macroscopic frictional force, the reaction mechnisms are sorted by the orbital angular momentum of the entrance channel from the classical deflection functions fitting elastic scattering. Moreover, inserting a transfer probability factor representing the Q-Window effect into the semi-classical angular distribution formula of Kalinkin and Grabowski, we obtain a formula for the differential cross-section per unit energy interval. The calculated results, including the elastic scattering angular distributions, energy spectrum and angular distributions of emitted α-particles in quasi-elastic process, complete fusion cross-section, fusion-fission cross-sections and the exitation functions of evaporated neutron, agree with the experimental data on the reaction 12C+209Bi reported by our Institute. 相似文献
8.
K. W. Schmid S. Krewald Amand Faessler L. Satpathy 《Zeitschrift für Physik A Hadrons and Nuclei》1974,271(2):149-159
Multi-Configuration-Hartree-Fock (MCHF) calculations with angular momentum projection before the variation of the internal degrees of freedom have been performed for the nuclei20Ne and22Ne. This procedure yields different correlated intrinsic states for the different members of a rotational band. Thus the angular momentum dependence of correlations has been studied. Experimentally, the ground state spectra of20Ne and22Ne show properties similar to the phase transitions observed in some rare earth nuclei which have been well reproduced through the present calculations. The calculated spectra andBE2-values show a significant improvement compared to the ones obtained by variation before the angular momentum projection is effected. 相似文献
9.
A multishell Hartree-Fock calculation for18O nucleus has been done with the Tabakin and Hamada-Johnston interactions followed by pairing correlations and angular momentum
projection. TheB(E2) transition rates have been reproduced with an effective charge of 1.5e for protons and 0.5e for neutrons, but the fit to energy levels is poor. An approximate alternative formalism has then been developed which casts
the eighteen-particle problem into a two-valence nucleon problem. The two valence nucleons interact through the RPA-type oscillation
modes of the core. Calculations with the two interactions mentioned above have reproduced roughly the uncorrelated projected
Hartree-Fock spectrum. Lastly, the excited band spectra of18O have been examined in the TDA approach followed by band mixing. 相似文献
10.
THE ENERGY SPECTRA OF 1f7/2 SHELL NUCLEI WITH NONIDENTICAL NUCLEONS CONFIGURATION AND THE TWO BODY SPIN-ORBIT COUPLING FORCES 下载免费PDF全文
The central and two body spin-orbit coupling forces as the residual interaction and the pure configuration are used to calculate the energy spectra of 1f7/2 shell nuclei (43Sc,44Ti,52Fe,53Fe,53Co) with nonidentical configuration. The consistency bettween the calculated energy spectra of the nuclei and the experimental data are rather satisfactory. 相似文献
11.
ZHAO You-Xiong GUO Zhong-Yan ZHU Yong-Tai ZHAN Wen-Long HU Xiao-Qing XI Hong-Fei LIU Guan-Hua ZHOU Jian-Qun FENG En-Pu YIN Shu-Zhi WEI Zhi-Yong Fan En-Jie MA Yu-Gang 《中国物理C(英文版)》1992,16(11):1022-1029
The energy spectra and angular distribution of α particles emitted from 12C induced reactions with 58Ni,115In and 197Au have been measured.Three moving sources of emitting α particle are clearly seen from invariant cross section distribution in velocity coordinates.The experimental data were analyzed by using three moving sources.Extracted parameters of the source with half-beam velocity are in agreement with the systematic values from Fermi Gas Model.The energy spectra and the extracted parameters for various targets are discussed.The low energy peak in energy spectra is possibly from the emitted α particle from equilibrium system after pre-equilibrium emission of target-like products.The energetic α particles are mainly from projectile fragmentation and projectile-like fragmentation. 相似文献
12.
Temperatures and Excitation Energies of Hot Nuclei in Reactions of 40Ar+natAg,209Bi at MeV/u 下载免费PDF全文
Yin Shuzhi Jin Weiyang Zhang Chun Jin Genming Zheng Jiwen Wu Enjiu Tan Jilian Li Zuyu Wang Sufang Song Mingtao Wu Heyu He Zhiyong Jiang Dongxing Qian Xing 《中国物理C(英文版)》1997,21(8):680-685
Coincidence measurements of fission fragment and light charged particle have been perfotrmed for the reactions of 40Ar+natAg,209Bi at E/A=25MeV using 4 PPAC and 11 sets of ΔE-E telescopes.Angular correlations of fission fragment were ploted as a function of the folding angle between the two detected fission fragments.The linear momentum transfer distributions were derived by measuring angular correlations.The backward spectra of light particles detected in coincidence with fission fragments having different average〈LMT〉are analyzed with Maxwell distribution.After some corrections the initial temperatures of the hot nuclei are determined from the energy spectra.The excitation energies corresponding to the different average〈LMT〉are obtained considering the reaction Q values and pre-equilibrum emission.In the central collision of the 40Ar+natAg,209Bi reactions,excitation energies are measured to be about 4.2MeV/u,2.4MeV/u and temperatures about 6.1MeV,5.5MeV,respecdvely.In semi-central collision,excitaionen energies are measured to be about 3.5MeV/u,1.9MeV/u and temperatures about 5.8MeV,4.8MeV respectively. 相似文献
13.
The decoupled bands of the odd-A La-isotopes are described by the angular momentum projection method. The coherent phonon state is assumed for the intrinsic wave function of the core. The present model covers the particle-vibrator and the particle-rotor coupling model. The results are in good agreement with the experimental energy spectra. 相似文献
14.
DEPENDENCE OF THE MECHANISM AND CROSS SECTION OF THE α PARTICLES EMITTED FROM 12C+64Ni REACTION ON INCIDENT ENERGY 下载免费PDF全文
WANG Da-Yan JIN Gen-Ming ZHANG Li WANG Xi-Ming YUE Hai-Kui ZHANG Bao-Guo 《中国物理C(英文版)》1987,11(1):92-97
Energy spectra and angular distributions of the particles emitted from 12C+64Ni reaction at eight energies in the region of 36.5MeV—69.4MeV are measured. The angular distributions of α particles change from forward peaked one to that peaked near by the grazing angle with decreasing incident energy. This result show that the emission mechanism of non-evaporation α particle is different in different energy regions. 相似文献
15.
H.R. Dalafi 《Nuclear Physics A》1975,252(1):42-46
An expression for angular momentum projected energy at small deformations is given which can, of course, be used for large deformations as well. Numerical calculations are carried out for the nucleus 120Sn. It is shown that the Hartree-Fock-Bogolyubov theory with angular momentum projection always produces non-spherical equilibrium shapes. 相似文献
16.
Employing a pairing-plus-quadrupole interaction hamiltonian and projecting out good angular momentum states from the cranked Hartree-Fock-Bogoliubov (CHFB) intrinsic wave functions the yrast spectra of 158Dy and 168Yb are calculated up to moderately high spins (Imax = 16) as to include the backbending region. Then the variation of pairing correlation, g-factor and rotational alignment of neutron spin as a function of total angular momentum is studied. The effect of particle number projection on the spin-projected CHFB wave functions is also investigated and is found to be unimportant for the calculation of g-factors. On the other hand, corrections of the excitation energies for number fluctuations in the CHFB wave functions are essential. Furthermore, looking at the distribution of the total projection quantum number K in various cranking wave functions we are able to throw some light on the K ≠ 0 nature of the aligned s-band.A variation-after-spin projection calculation strictly for the axial shape, without cranking, is also carried out for both the nuclei considered here. In the low-spin region this numerically “cheaper” scheme produces energy spectra similar to that of the CHFB method, and may thus be used to readjust the interaction parameters. 相似文献
17.
The fission cross sections and the evaporation residue cross sections for 12C+209Bi and 14N+Pb reactions were measured with the gold surface barrier silicon detectors and the mica nuclear track detectors.The critical angular momentum ler was deduced from the measured evaporation residue cross section σer on the basis of the sharp-off model.The fission barrier with the particular angular momentum i derived from the condition Γf/Γn=1 at l=le The angular momentum effect of the fission barrier was studied experimentally. 相似文献
18.
We present calculations of electromagnetic properties of158Dy and164Dy based on the solution of the self-consistent cranking model and approximate angular momentum projection technique developed earlier. The calculated values compare fairly well with the existing experimental data. 相似文献
19.
Lin Lu 《Nuclear Physics A》1984,431(2):230-236
A fast computational method for approximate angular momentum projection is proposed for low-lying deformed nuclear states. The accuracy of the method is demonstrated by calculating the low-lying states of the ground-state band and the two 0+ excited bands in 168Er with good experimental comparison. 相似文献
20.
DAI Guang-Xi JIN Gen-Ming YUAN Shuang-Gui GUO Zhong-Yan ZENG Wen-Bing CHEN Ju-Sheng LI Zu-Yu WANG Da-Yan XU Guo-Jun 《中国物理C(英文版)》1983,7(1):86-94
The energy spectra and angular distributions of α-particle emitted from 12C-induced reactions with 159Tb, Ag and 89Y targets have been measured. Meanwhile the emitted deutron's angular distributions with 159Tb and 89Y targets and proton's with 89Y target have been also obtained.
The α-energy spectra associated with mentioned reactions have bell-like shape with probable energy near coulomb barrier. However, the main characteristic of the α-angular distribution for 159Tb and Ag targets is peaked at or near the grazing angles. For the case of 89Y target, α-differential cross-sections monotonically decrease with angles beyond 40º. The angular distributions of potons and deutrons nearly decrease exponentially.
The measured α-angular distributions could be divided into two components, one coming from α-evaporation is isotropic, another is anisotropic. The anisotropic component may be explained incomplete-fusion process in which the cross-section can be reproduced by a "Sum-Rule Model" due to J.Wliczynski.
In order to explain the anisotropic component of emitted α-particle, we propose in complete fusion model with a strong-damped sticking rotation, in which the rotation angles and interaction time of the composite system are also estimated. 相似文献
The α-energy spectra associated with mentioned reactions have bell-like shape with probable energy near coulomb barrier. However, the main characteristic of the α-angular distribution for 159Tb and Ag targets is peaked at or near the grazing angles. For the case of 89Y target, α-differential cross-sections monotonically decrease with angles beyond 40º. The angular distributions of potons and deutrons nearly decrease exponentially.
The measured α-angular distributions could be divided into two components, one coming from α-evaporation is isotropic, another is anisotropic. The anisotropic component may be explained incomplete-fusion process in which the cross-section can be reproduced by a "Sum-Rule Model" due to J.Wliczynski.
In order to explain the anisotropic component of emitted α-particle, we propose in complete fusion model with a strong-damped sticking rotation, in which the rotation angles and interaction time of the composite system are also estimated. 相似文献