首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 765 毫秒
1.
Three-body exit channel in the reaction 12C+16O at 56MeV has been studied by using measurement of the coincidence between the two changed particles.The projected spectra of the coinsidence between the two α-particles shows that the channel α+24Mg is the main intermediate process of three-body exit channel α12+20Ne in the reaction 12C+16O at 56MeV.The analysis of theoretical calculation showed that the sum of sequential decay and statistical break-up fit the experimental spectra satisfactorily.  相似文献   

2.
The angular distributions for elatic scattering of the two systems,16O+94Zr at energies 52,57,59,62,72,82 and 92 MeV and 16O+116Sn at energies 57,59,62,67,72,82 and 92 MeV have been measured.The scattered ions were datected by the Beijing Q3D magnetic spectrometer and its heavy ion focal plane detector.The optical model analysis of the data was made with the Coupled Channels code ECIS, and the optical potential parameters have been obtained by fitting the data.Within the limited data,the phenomenon of the ‘threshold anomaly’is observed.  相似文献   

3.
The fragmentation cross sections of reactions ^12C+^2H, ^12C, ^14N, ^16O at beam energies from 50 to 100 MeV/nucleon are investigated using the isospin-dependent Boltzmann-Langevin equation model. It is found that fragment species increase approximately with the increasing target mass. The fragment species and some fragments production cross sections in reactions of ^12C+^12C, ^14N, ^16O show an obvious variation at the beam energies from 50 to 80 MeV/nucleon. However the calculated fragment production cross sections do not change much when the incident energy increases from 80 to 100 MeV/nucleon.  相似文献   

4.
The binding problem of isobar Δ(1232) in 4He 12C and 16O systems is studied in detail by Hartree-Fock method. The OBEP is used for the nucleon-nucleon potential and the nucleon-Δ(1232) interaction. The calculated results show that Δ(1232) can be bound only in 4He and not in 12C and 16O systems.  相似文献   

5.
Angular distributions and differential range distributions have been measured with nuclear chemistry techniques for 20 target residues from the reactions of 115In with 92 and 71MeV 16O ions.In terms of the increase of impact parameter,the results indicate continuous evolution of the reaction mechanisms from complete fusion,incomplete fusion to direct reaction involving steadily decreasing transfer of mass and momentum.Contribution of incomplete fusion in 16O+115In reaction is significantly larger than that in 16O+65Cu reaction.  相似文献   

6.
The oscillatory structure appeared in the differential cross section of the reaction for 16O(16O, 12C)20Ne may be explained by particle transfer from covalent channel to ionic channel in the nuclear molecular orbital theory.  相似文献   

7.
8.
Using Glauber's multiple scattering theory, and using coherent fluctuation nuclearmodel, the double charge exchange (DEC) reaction cross sections for πon 16O and 18Ohave been calculated. The calculated values of the ratio of σ(18O(π+,π-)18Ne)g.s. toσ(16O(π+,π-)16Ne)g.s. fit the experimental data quite well. Just as predicted by ourcalculation, the angular distribution of 18O(π+,π-)18Neg.s. in a recent experiment,exhibits an evident dip around 23°.  相似文献   

9.
The Eta-24Mg mesic mucleus and the Eta-32S mesic nucleus are considered as the 12C-Eta-12C and 16O-Eta-16O three body systems respectively.With the separable potentials which include only S-wave Eta-12C and Eta-13O interadtions as the effective interactions,the Schrodinger equa tions of the systems are solved in the Born-Oppenheimer approximation.The two-center problems are solved exactly first,and then the binding-energies of Eta-24Mg and Eta-32S are calculated.The calculated results are satisfactory.  相似文献   

10.
Elastic scattering angular distributions of the 14^N+16^O system and the angular distributions of transfer reaction 16^O(14^N,13^C)17^F at ELab=76.2 MeV and 57 MeV have been measured and calculated by means of the exact finiterange distorted-wave Born approximation with the PTOLEMY code. The optical potential parameters for the weakly bound nuclear system 17^F+13^C have been deduced and applied to analyse the elastic scattering angular distributions of the similar systems 17^F+12^C and 17^F+14^N which are taken from literature. The result shows that the transfer reaction with stable projectile and target combination can be used as an alternative method to extract the optical potential parameters for the weakly bound nuclear system.  相似文献   

11.
The angular distributions and Wilczynski plots of emitted fragments from He to O in reaction of 16O+64Ni at 96MeV have been measured.The DIC cross section and intereaction time were obtained.DIC character of the reaction was discussed.The trace which shows that the emitted fragments of He and Li mainly come from the evaporation process of compound nuclei emerged.  相似文献   

12.
High spin states in 170Ta have been studied via 159Tb(16O,5nγ)170Ta reaction at 105MeV.Three rotational bands are observed,among which one coupled band and an unfavored ΔI=2 E2 squence are newly found in this owrk.The possible quasiparticle configurations of these bands are discussed.  相似文献   

13.
Relativistic microscopic optical potential of nucleon-nucleus is derived from the relativistic Brueckner-Bethe-Goldstone (RBBG) equation.The complex effective mass of a nucleon is determined by a fit to 200MeV p-40Ca scattering data.The relativistic microscopic optical potentials with this effective mass are obtained from RBBG for p-16O,40Ca,90Zr and 208Pb scattering in energy range from 160 to 180MeV.The microscopic optical potential is used to study the proton-40Ca scattering problem at 200MeV.The results,such as defferential cross section,analyzing power and spin rotation function are compared with those calculated from phenomenological relativistic optical potential.  相似文献   

14.
Defect engineering for SiO2 precipitation is investigated using He-ion implantation as the first stage of separation by implanted oxygen (SIMOX). Cavities axe created in Si by implantation with helium ions. After thermal annealing at different temperatures, the sample is implanted with 120 keV 8.0 ×1016 cm 2 0 ions. The Q ion energy is chosen such that the peak of the concentration distribution is centred at the cavity band. For comparison, another sample is implanted with O ions alone. Cross-sectionM transmission electron microscopy (XTEM), Fourier transform infrared absorbance spectrometry (FTIR) and atomic force microscopy (AFM) measurements are used to investigate the samples. The results show that a narrow nano-cavity layer is found to be excellent nucleation sites that effectively assisted SiO2 formation and released crystal lattice strain associated with silicon oxidation.  相似文献   

15.
The high spin states in 126Ba were populated by means of the reaction 116Sn (16O,2p4n)126Ba at the beam energy of 73MeV. Lifetimes of the states around the backbend in the yeast band were measured by using the Doppler shift attenuation method. The corresponding normalized B(E2) values are pronouncedly reduced for the 10+ and 12+ states. The experimental results are compared with the theoretical predictions of the particle-rotor model.  相似文献   

16.
Production of helium projectile fragments in 16O-emulsion interactions at 60 A GeV is investigated. The total charge changing and partial production cross-sections are measured experimentally on the basis of helium multiplicity. The multiplicity distribution of helium projectile fragments obeys a KNO scaling. In the peripheral collision of 16O at 60 A GeV in nuclear emulsion, the production of target fragments depends on the multiplicity of helium projectile fragments linearly. The averge multiplicity of target fragments decreases with the increasing of the number of helium projectile fragments which can be well expliained by the model of participant-spectator (the nuclear geometric model) of nucleus-nucleus interactions.  相似文献   

17.
By using ΔE-E telescope and the time of flight detector, the energy spectra of products between 6Li and 16O were measured for the reaction 12C+27Al, at 61.8MeV. The contour plots of differential cross section in c.m. system and the angular distributions of emitted fragments were obtained. The calculated values of fully relaxed energies in deep inelastic collistions agree with the experimental values. The mean interaction time of di-nuclear system was estimated as from 1×10-21s to 1.4×10-22s  相似文献   

18.
Angular distribution of the scattering of 31.2 MeV-α-particle by the nucleus 10,11B is measured. Our results show that there is anomalous phenomenon in the case of 10B but there is not in 11B. Calculations and analysis are made with the optical model adding the Regge-Pole model. The results show that for the nucleus of 1p-shell, such as α+16O, the result of the calculation agrees very well with the experimental measurements but it fails in α+10B. As to the analysis with the double v-power optieal model for α+16O, the agreement is somewhat a little worse than the former's and the result for α+10B agrees only qualitatively with the experimental measurement. It is well known that the analysis with these models for α+40Ca agrees very well with the experimental data. Thus we may come to the conclusion that the mechanism of ALAS of the nucleus of 2s-1d shell is different from that of 1p-shell, and the mechanisms of ALAS of the nuclei of 1p-shell are also different.  相似文献   

19.
The mechanism of transfering a cluster of nucleons between two colliding nuclei is considered to explain the backward angle oscillatory rise in the differential cross section of the elastic scattering between certain nuclei, such as 16O+24Mg or 20Ne+24Mg. The nuclear molecular orbit approximation theory is applied. For one-step transfer, if the parameter involved is assumed to be adjustable, the numerical calculations can be made to fit the experimental results naturally.  相似文献   

20.
Resonant structures appeared in the excitation functions for the 16O+20Ne elastic scattering have been studied by using the nuclear molecular orbital theory.The theoretical results agree well with the experimental data.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号