46.8MeV的p+12C非弹性散射

在Glauber多重散射理论框架下，使用跃迁密度方法和三种N湮没势，计算了46.8MeV的反质子在¹²C上的非弹性散射微分截面. 理论曲线与实验数据符合得较好. 关键词： Glauber理论 反质子 非弹性散射 湮没势 跃迁密度     

Study of ~3He inelastic scattering on 13C and 14C at 37.9 MeV

The differential cross sections of elastic and inelastic scattering of ~3He ions on ~（13）C and ~（14）C have been studied at an energy of 37.9 MeV with a double folding model based on M3Y-Reid effective nucleon-nucleon interaction.The resulted parameters have been used for the standard Distorted Wave Born Approximation calculations of angular distributions corresponding to different excitations levels of ~（13）C and ~（14）C and deformation parameters have been deduced.     

Elastic and inelastic scattering of 185 MeV protons from 12C

The polarization of 185 MeV protons in elastic scattering and in the excitation of the 2⁺ state at 4.44 MeV and the 0⁺ state at 7.65 MeV in ¹²C has been measured in the angular region 2°–60°. Optical model calculations are performed for the elastic scattering. Angular distributions for the inelastic scattering from the 2⁺ state at 4.44 MeV and the 3^? state at 9.64 MeV are calculated in the distorted-wave impulse approximation (DWIA) as well as in the distorted-wave Born approximation (DWBA).     

Study of ~3He inelastic scattering on ~(13)C and ~(14)C at 37.9 MeV

The differential cross sections of elastic and inelastic scattering of ³He ions on ¹³C and ¹⁴C have been studied at an energy of 37.9 MeV with a double folding model based on M3Y-Reid effective nucleon-nucleon interaction. The resulted parameters have been used for the standard Distorted Wave Born Approximation calculations of angular distributions corresponding to different excitations levels of ¹³C and ¹⁴C and deformation parameters have been deduced.     

Elastic scattering of intermediate energy protons on4He and12C

The elastic angular distribution and polarization of ～1 GeV protons on⁴He and¹²C have been analysed using the recently proposed correlation expansion for the Glauber amplitude by retaining terms up to three-body density only. The calculations include Coulomb and spin effects. Using realistic form factors for target nuclei it is found that we need to consider only up to the second-order density term to provide a satisfactory explanation of both kinds of experimental data in the available momentum transfer region. The contribution of the three-body density term is only marginal except in⁴He differential cross-section in the cm angular range 45°<θ _cm<65°.     

Elastic and inelastic scattering of 58Ni +90,94Zr

Pure elastic and inelastic scattering cross sections have been measured for the systems ⁵⁸Ni +^90,94Zr at energies near the Coulomb barrier where not only quasi-elastic and fusion but also deep-inelastic process come into play. Coupled channels calculations including both projectile and target inelastic excitations can successfully explain the elastic and inelastic scattering angular distributions with an energy-independent semi-empirical bare potential. The calculation reproduces also the sum of the total quasi-elastic, fusion and deep-inelastic cross sections. Received: 14 September 1998 / Revised version: 21 October 1998     

Fluctuations in12C+24Mg elastic and inelastic scattering

The data on the ϑ_c.m.=180° excitation functions of¹²C+²⁴Mg,¹²C* (4.43 MeV)+²⁴Mg and¹²C+²⁴Mg*(1.36 MeV) from 12.27 to 22.80 MeV, 16.53 to 27.47 MeV, and 11.33 to 26.40 MeV(c.m.) respectively have been subjected to statistical analysis. The effect of averaging interval, employed for data reduction, on the coherence widths as obtained from the autocorrelation function has been studied. The fluctuating features of the cross-sections turn out to be consistent with the statistical model expectations.     

Elastic scattering of intermediate-energy weakly bound particles on 12C nuclei

The differential cross-section for elastic scattering of deuterons at 700 MeV, ⁶Li and ⁶He at 2.07 GeV nuclei on ¹²C nucleus is calculated under the assumption of two-cluster (for deuterons and ⁶Li) and three-cluster (for ⁶He) structure of incident particle. For ⁶Li-¹²C and ⁶He-¹²C elastic scattering it is shown that there are quantitative distinctions in the behaviour of the observables calculated in the above approaches. Received: 13 October 1999 / Accepted: 3 January 2001     

Simulation of 12C+12C elastic scattering at high energy by using the Monte Carlo method

The Monte Carlo method is used to simulate the ¹²C+¹²C reaction process. Taking into account the size of the incident ¹²C beam spot and the thickness of the ¹²C target, the distributions of scattered ¹²C on the MWPC and the CsI detectors at a detective distance have been simulated. In order to separate elastic scattering from the inelastic scattering with 4.4 MeV excited energy, we set several variables: the kinetic energy of incident ¹²C, the thickness of the ¹²C target, the ratio of the excited state, the wire spacing of the MWPC, the energy resolution of the CsI detector and the time resolution of the plastic scintillator. From the simulation results, the preliminary establishment of the experiment system can be determined to be that the beam size of the incident ¹²C is φ 5 mm, the incident kinetic energy is 200-400 A MeV, the target thickness is 2 mm, the ratio of the excited state is 20%, the ight distance of scattered ¹²C is 3 m, the energy resolution of the CsI detectors is 1%, the time resolution of the plastic scintillator is 0.5%, and the size of the CsI detectors is 7 cm×7 cm, and we need at least 16 CsI detectors to cover a 0° to 5° angular distribution.     

Analysis of inelastic neutron scattering results on model compounds of the nitrogenous bases of the nucleotides

The role that model compounds can play in understanding the vibrational eigenvectors of molecules is discussed. Assigning the spectra of model compounds is of particular importance and the individual-scaling approach, that has been used with isolated molecule ab-initio calculations, is outlined. Special emphasis is given to recent work on assigning the spectra of three 5–6 heterobicyclic systems; indole, benzimidazole and isatin.      

Oscillator strength study of the excitations of valence-shell of C2H2 by high-resolution inelastic x-ray scattering

The oscillator strengths of the valence-shell excitations of C₂H₂ are extremely important for testing theoretical models and studying interstellar gases. In this study, the high-resolution inelastic x-ray scattering (IXS) method is adopted to determine the generalized oscillator strengths (GOSs) of the valence-shell excitations of C₂H₂ at a photon energy of 10 keV. The GOSs are extrapolated to their zero limit to obtain the corresponding optical oscillator strengths (OOSs). Through taking a completely different experimental method of the IXS, the present results offer the high energy limit for electron collision to satisfy the first Born approximation (FBA) and cross-check the previous experimental and theoretical results independently. The comparisons indicate that an electron collision energy of 1500 eV is not enough for C₂H₂ to satisfy the FBA for the large squared momentum transfer, and the line saturation effect limits the accuracy of the OOSs measured by the photoabsorption method.     

Elastic and inelastic scattering of 12C by 12C in the energy range between 10 and 37.6 MeV

The elastic and inelastic scattering of ¹²C by ¹²C has been measured over a wide angular range employing a kinematical analysis with the help of position-sensitive detectors. The bombarding energy was varied in 200 keV steps between 10 and 37.6 MeV. The cross sections are analysed in the framework of compound fluctuations and the direct reaction model.     

Elastic scattering via quark structure of nucleons

In the framework of the Glauber multiple-scattering theory, the elastic collisions of proton-proton (pp) at the center-of-mass energies = 23.5, 30.7, 44.7, and 52.8 GeV and alpha-proton (p) at = 88 and 89 GeV are analyzed by considering the quark structure of their constituents. The differential cross-section containing the full multiple-scattering series between their quarks is calculated using Gaussian forms for the quark density and quark-quark (QQ) scattering amplitudes. The results obtained from the quark model and the conventional nucleon model are compared with the experimental data. The comparison shows that the nucleon model reproduces the experimental data more satisfactorily than the quark model, and both approaches have limited success in describing the data at such energies. The agreement with the experimental data is improved by the inclusion of the phase variation.     

Low energy ion scattering by atomic steps on the single crystal surface

The energy, angular distributions and trajectories of particles scattered on surfaces of Ni(100) and Cu(100), with both ideal and damaged, and semi-infinite and isolated atomic steps, have been calculated. It has been shown that from the correlation between the experimental and calculated energy distributions of the scattered particles, one may determine the spatial extension of the isolated atomic steps and the distance between them on the single crystal surface damaged by ion bombardment. The energy and angular distributions of ions dechanneled from semi-infinite steps on the GaP(100) surface have been presented. It has been shown that the dechanneling ions form the characteristic peaks in the angular and energy distributions of the scattered particles.     

Intermediate energy elastic scattering of protons on 24Mg in the $ \alpha$ -cluster model with dispersion

The -cluster model with dispersion has been developed for the case of the ²⁴Mg nucleus. The ²⁴Mg nucleus is considered as composed of the core ( ¹⁶O nucleus) and two -clusters that form a dumbbell configuration and are arranged with the most probability inside the core. In the calculations the -cluster structure of the core has been taken into account. On the basis of the multiple diffraction scattering theory the differential cross-section and the polarization observables for the elastic p - ²⁴Mg scattering at 800 and 250MeV have been calculated. The results obtained are in agreement with the existing experimental data.