17C反应截面测量及有限力程Glauber模型分析

用透射法测量了能量为79AMeV的¹⁷C在¹²C反应靶上的反应截面;利用有限力程Glauber模型对¹⁷C的密度分布进行了分析.由高能区(965AMeV)相互作用截面数据分析认为¹⁷C具有谐振子密度分布,但拟合本实验结果及高能区实验数据发现,¹⁷C的中子密度分布中存在一个尾巴;假设¹⁷C密度为芯核加单粒子密度分布形式,分析认为¹⁷C的价中子主要处于1d5/2?轨道.     

On the Gross Structure of Fusion Cross Section for 16O+12C System

The gross structure appeared in the total fusion cross section for ¹⁶O+¹²C system is studied by using the LCNO theory and the folding model of the paritydependent potential.The experimental data of the fusion cross section,elastic scattering excitation functions and angular distributions for this system are well explained.     

Measurements of Reaction Cross Section for F Isotopes and Possible Proton Skin Structure for 17F

The reaction cross sections σ R of F isotopes on carbon target were measured at intermediate energies via the transmission method. It was found that the reaction cross section of ¹⁷F has a little enhancement compared with that of its neighbor isotopes. The difference factor d has been deduced from the measured σ R by using the BUU model and Glauber model. It is enhanced also for ¹⁷F compared with its neighbor isotopes. From the above analysis, a possible proton skin structure is suggested for ¹⁷F.     

Excitation Function for 12C+12C Elastic Scattering

An energy dependent optical potential for ¹²C+¹²C system is established based on the analyses of the angular distributions of the elastic scattering in the energy range of 70-160MeV. This potential can well reproduce the excitation function for 12C+12C elastic scattering in the same energy range.     

Optical Potential Parameters for Halo Nucleus System ^6He＋^12C from Transfer Reaction ^11B（^7Li, ^6He）^12C

The optical potential parameters for the halo nucleus system ^6He＋^12C are extracted from fits to the measured angular distributions of ^11B（^7Li, ^6He）12C reaction at energies of 18.3 and 28.3MeV with distorted-wave Born approximation analysis. The characters of the obtained optical potentiM parameters are basically consistent with the results extracted from the fits to the elastic-scattering angular distributions in the literature.     

Dispersion Optical Model Analysis of the Neutron Cross Section Anomalv for 16O

The optical model of ¹⁶O is studied based on the dispetsion relation theory at neutron energy up to 20MeV.The total cross section anomaly is removed essendally at low energies for ¹⁶O.     

Angular Distribution of the 12C(6He, 7Li)11B Reaction

Angular distribution of the ¹²C(⁶He,⁷Li)¹¹B transfer reaction is measured with a secondary ⁶He beam of 36.4MeV for the first time. The experimental angular distribution is well reproduced by the distorted-wave Born approximation (DWBA) calculation. The success of the present experiment shows that it is feasible to measure one-nucleon transfer reaction on a light nucleus target with the secondary beam facility of the HI-13 tandem accelerator at China Institute of Atomic Energy (CIAE), Beijing.     

Measurement of Angular Cross Correlation of the Cross Section Fluctuation in Dissipative Collision 27Al+27Al

The excitation function was measured from θ_lab=10.4° to 57.4° in dissipative collision ²⁷Al+²⁷Al with incident energy ranging from 114 to 123 MeV in step of 200 keV. The Angular-cross Correlation Functions (ACFs) of cross section fluctuation within large angle region were obtained through experiment for the first time. It is found that the angular coherent width is at least 40°. It is interesting that the ACFs is not simple bell shape but shows strong asymmetry. The over-all behavior is that ACF varies more quickly for the backward angles. Itis also noticed that the cross section fluctuation in the forward angle region (θ_cm<70°) shows much stronger angular coherence than in the backward angle region (θ_cm>70°). This angular dependence may be attributed to the coherent rotation effect of intermediate dinuclear system.     

Optical Potential Parameters of Weakly Bound Nuclear System 17F+13C

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.     

Quasi-Elastic Scattering of 16C from 12C at 47.5 MeV/Nucleon

Differential cross sections for the quasi-elastic scattering of^16 C at 47.5 MeV/nucleon from ^12 C target are measured.Coupled-channels calculations are carried out and the optical potential parameters are obtained by fitting the experimental angular distribution.     

能量修正的Glauber模型对中能反应总截面的影响

叙述了对Glauber模型中的透射系数进行半经验的能量修正,并利用该修正模型计算了^12—14C,⁶Li,⁷Be,⁸B+¹²C和⁶Li,⁷Be,⁸B+⁹Be以及²⁰Ne+¹²C,¹²C+²⁷Al等系统的激发函数(能区范围10—1000MeV/u),经与实验值比较,能量修正的Glauber理论计算值能够很好地描述中能条件下的反应总截面实验测量值.     

MEASUREMENT OF COMPLETE FUSION CROSS SECTION OF 12C+159Tb,12C+165Ho

Complete fusion cross sections have been measured for ¹²C+¹⁵⁹Tb and ¹²C+¹⁶⁵Ho reactions by using K-X rays of evaporation residues with Si(Li)spectrometer.The half-lives of evaporation residues and its yield distributions as a function of incident energy have also been obtained.The experimental values for the complete fusion cross section were compared with the theoretical ones.     

46.7MeV/u 12C轰击159Tb、197Au和209Bi的裂变测量及分析

用46.7MeV/u~(12)C轰击~(159)Tb、~(197)Au、~(209)Bi,测量关联裂片的速度和角度,研究了线性动量转移(LMT)、质量和出平面角分布,提取了核温度,应用级联两体统计衰变理论进行了拟合与解释,结果表明:在～50MeV/u入射能的中能重离子碰撞中,以非完全熔合方式形成了核温度高达4～5MeV的类复合核,其后通过裂变、蒸发级联统计两体衰变而退激。 The velocities and angles of fission partners emitted from reactions in ~(12)C+~(159)Tb, ~(197)Au,~(209)Bi systems with bombarding energy of 46.7MeV/u are measured. The linear momentum transferfrom projectile to target、mass and out-of-reaction plane angle distributions of fission fragments arestudied, and the temperatures of the target residues are extracted. These results have been explained by statistical binary decay model. It seems that the compound-likesystem with high temperature...     

12C(50MeV/u)+209Bi反应中线性动量耗散机制研究

本文介绍~(12)C(50MeV/u)+~(209)Bi核反应中线性动量转移LMT分布的实验测定及结果,利用BUU方程对该碰撞过程进行了动力学模拟计算,对理论计算所得LMT分布和实验分布进行了比较和讨论。 The experimental measurements and results of LMT distribution in ~(12)C(50MeV/u)+~(208)Bi reaction are reported. By using BUU equation for nucleus-nucleus collision process, the dynamicimitation calculation is made. The theoretical calculated LMT distribution is compared with theexperimental one and some discussion has been reviewed.     

应用二维谱学技术归属泰妥拉唑的1H和13C NMR

应用DEPT（无畸变极化转移增强谱）、HMQC（异核多量子相干谱）、HMBC（异核多键相干谱）、¹H-¹H COSY（相关谱）、NOESY（核欧沃豪斯谱）和 TOCSY（全相关谱）谱学技术,对泰妥拉唑所有的氢进行了归属. 不对称硫原子引起邻接CH₂ 2个氢化学位移不等价;该2个氢相互偶合,其偶合常数为12.9 Hz;借助DEPT谱,2个甲氧基被区别;借助DEPT和TOCSY谱,另2个与碳相连的甲基被区分;利用HMBC谱,所有的碳峰可以归属.      

SYMMETRY OF THE ROTATION+VIBRATION SPECTRA FOR NUCLEAR MOLECULE 12C+12C

The rotation-vibration spectra of nuclear molecule ¹²C+¹²C is chassified by the irreducible representations of group U(5). It is shown that the symmetry of rotation-vibration levels of nuclear molecule ¹²C+¹²C are discribed by means of dynamical symmetry U(5)U(4)O(4)O(3).     

Non-Reproducibility of the Cross Sections of the Products Induced from Dissipative Reaction of 17F+27Al

The differential cross sections of the dissipative products B, C, N, O, F, Ne, Na and Mg induced from the reactions of ¹⁹F+²⁷Al at two incident energies have been measured at the HI-13 tandem accelerator, Beijing. In the case of a fixed beam incident energy 114MeV or 118.75MeV respectively, identical reaction system and the same detection system, 20 target points in steps of 2mm on a 10mm×50mm rectangular Al foil have been bombarded. The experimental results indicate that the probability distribution of the cross sections is much wider than a standard Gaussian distribution. This non-reproducibility of the cross sections can't be interpreted by the statistical property of a finite count rate.     

SYMMETRICAL ANALYSIS OF 9Be AND 12C HYPERNUCLEI

By analyzing the experimental data of the hypernuclei, we propose a hypothesisthat the single baryon binding energy satisfies the SU(3) uintary symmetry. By thissuggestion, some experimental facts in this field can be explained and we also proposethe possibility of the existence of excited states of the hyper [1] nuclei. Some propertiesof this [1] hyper-nuclei is also pointed out.     

THE MEASUREMENT OF COMPLETE FUSION CROSS-SECTIONS FOR THE REACTIONS 12C+27Al, 12C+209Bi AND 14N+Pb

Mica track detectors were used for the measurement of evaporation residues and fission fragments of compound nuclei formed in ¹²C+²⁷Al, ¹²C+²⁰⁹Bi and ¹⁴N+Pb reactions. The complete fusion cross-sections and excitation functions were then obtained. By using the sharp cut-off model approximation, the values of the critical angular momenta were extracted from the complete fusion cross-sections. The results obtained were compared with the calculations based on current theories for critical angular momentum; they were found to agree within experimental uncertainties.     

THE MASSIVE TRANSFER IN 12C+197Au REACTION

In this paper, we present energy spectra and angular distributions for the α-par-ticles emitted in the reaction of ¹²C+¹⁹⁷Au at 64 and 67 MeV and for α, Be and B emittedin the reaction at 71.5 MeV. The most-probable energles of the variousproducts emittedin this reaction decrease.with decreasing incident energy. The angular distributions peak near grazing angle.The peak position of the angular distributions shift from--80°to--120°while the projec-tile energy decreases from 71.5 MeV to 64 MeV. These all show the features of the transferreaction. The ⁶Li product also has been measured and the ⁸Be particle emitted from thisreaction was detected at 90°to the beam direction using α-α coincident technique at 71.5MeV. The coross section of the ³Be is only few percent at the same angle.