共查询到20条相似文献,搜索用时 31 毫秒
1.
WANG Qi TIAN Wen-Dong LI Song-Lin JIANG Zhong-He DONG Yu-Chuan LI Zhi-Chang LU Xiu-Qin ZHAO Kui FU Chang-Bo LIU Jian-Cheng JIANG Hua HU Gui-Qing 《中国物理C(英文版)》2002,26(2):141-147
Two independent measurements of excitation functions in the dissipative collisions of 19F+93Nb have been performed at incident energies from 100 to 108 MeV in steps of 250 keV. The two measurements differed by the thickness of the target foils, 70μg/cm2 and 71μg/cm2, respectively. All the other experimental conditions, the accelerator, the incident energies and steps, the scattering chamber, the detection system, the electronics, the acquisition system and all the parameters selected in the two measurements, were kept to be identical in both experiments. The data indicate non-reproducibility of the non-self averaging oscillating yields in the two independent measurements. The indication of the non-reproducibility of the cross sections is discussed. 相似文献
2.
LIU Shao-Xiang 《中国物理C(英文版)》1985,9(3):321-326
The angular distribution has been measured for elastic scattering on 40Ar with 11B and for the single proton transfer reaction 40Ar(11B, 10Be)41K at the incident beam energy of 50 MeV. The elastic scattering cross section has been fitted in terms of the optical model. The EFR-DWBA aproach with recoil effect has been used to analyze the differential cross section. The spectroscopic factor was extracted. 相似文献
3.
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. 相似文献
4.
范凤英 郑涛 叶沿林 江栋兴 华辉 李智焕 葛愉成 李湘庆 楼建玲 史帆 吕林辉 曹中鑫 聂鹏煊 李奇特 宋玉收 卢飞 徐瑚珊 胡正国 王猛 张雪荧 李琛 陈若富 唐彬 徐治国 岳珂 张亚鹏 臧永东 章学恒 姚向武 陈金达 涂小林 张洁 武大鹏 白真 《中国物理快报》2009,26(8):74-77
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. 相似文献
5.
Fragmentation Cross Sections of 12C on Different Targets at Beam Energies from 50 to 100MeV/Nucleon 下载免费PDF全文
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
6.
Measurement of Angular Cross Correlation of the Cross Section Fluctuation in Dissipative Collision 27Al+27Al 下载免费PDF全文
The excitation function was measured from θlab=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 (θcm<70°) shows much stronger angular coherence than in the backward angle region (θcm>70°). This angular dependence may be attributed to the coherent rotation effect of intermediate dinuclear system. 相似文献
7.
By means of using an isospin-dependent Boltzmann-Langevin equation which includes isospin-dependent symmetry energy, Coulomb energy, isospin-dependent nucleon-nucleon cross sections, Pauli blocking, and initialization, the radial expansion flow of reaction systems 40Ca+58Ni and 40Ca+58Fe at 53, 100, 150, and 200 MeV/u in the central collisions were studied. It has shown that the more neutron rich system exhibits smaller radial expansion flow. It was found that the neutron rich system had smaller threshold energy which may provide a new method to determine the isospin dependent nuclear equation of state from calculated result and linear fitting result. 相似文献
8.
庞丹阳叶沿林 郑涛李智焕 李湘庆葛愉成 华辉吴翠娥 楼建玲卢飞 范凤英A. Ozawa Y. Yamaguchi R. Kanungo D. Fang I.Tanihata 《中国物理快报》2007,24(10):2785-2788
The inclusive differential cross sections of the ^7 Li nucleus in a reaction induced by ^6He on a ^9Be target are measured at an incident energy of 25 MeV/nucleon. Finite-range distorted-wave Born approximation calculations suggest that these ^7 Li particles are formed in a direct single-proton pickup reaction ^9Be(^6He,^7 Li)^8Li. The experimental data can be well reproduced by taking into account of the contributions of both the ground states and the first excited states of ^7Li and ^8Li. 相似文献
9.
Non-reproducibility of the Cross Sections Measured in the Dissipative Collisions of 19F+93Nb 下载免费PDF全文
WANG Qi TIAN WenDong LI SongLin JIANG ZhongHe LI ZhiChang LU XiuQin ZHAO Kui FU ChangBo LIU JianCheng JIANG Hua HU GuiQing 《中国物理C(英文版)》2000,24(11):1060-1065
Two independent measurements of excitation functions for the 19F+93Nb dissipative heavy ion collisions have been performed at incident energies from 100 to 108 MeV in steps of 250 keV. The two measurements differed by two target foils, 70 and 71μg/cm2, respectively. All the other experimental conditions were kept to be identical in hath experiments. The data indicate nonreptaludbility of the non-self-averaging oscillating yields in the two measurements. This supports recent theoretical predictions of extreme sensitivity and chaos in complex quantum collisions. 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 pre-equilibrium correction for the nuclear reactions induced by fast neutron is considered as follows: the nuclear reaction processes with the exciton number equal to or larger than five can still be described by the statistical theory of the nuclear reaction. The particle emission processes, in which less than five excitons are involved, are calculated by means of the exciton model and the γ emission of one exciton state is calculated by the direct capture mechanism. For the three-exciton state, only the semidirect capture mechanism, which plays the main role in the researched energy region, is taken into account. The interference effect between the direct and semidirect capture is also considered. The radiative capture cross sections for 40Ca and 208Pb in the neutron incident energy region from 3 MeV to 20 MeV are calculated and a better coincidence with the experimental values is obtained. At the same time, the contribution to the (n, γ) reaction cross sections of the γ emissions before and after statistical equilibriums as well as the characteristics of the direct capture, semidirect capture and their interferece terms are discussed. 相似文献
12.
Measurement of Excitation Function and Analysis of StatisticalProperty in 27Al+27Al mssipative Reaction 下载免费PDF全文
The angular distribuhon in the range of 0cm=50°—90° and excitation funchon of the reachon products in heavy ion dissipahve reachon 27Al+27Al were measured, in the incident energy region from 114MeV to 120MeV with 200keV step. The statishcal property of the fluctuation of the excitation funchon in heavy ion dissipative reaction was discussed based on the integration of the macro outgoing channels. 相似文献
13.
Analysis of the Energy Autocorrelation Functions in Dissipative Heavy Ion Collision of 27Al+27Al 下载免费PDF全文
The excitation functions of the dissipative fragments emitted from the reaction of 27Al+27Al have been measured in the energy region from 114MeV to 127MeV in steps of 200keV. The detection system covered continuous angles from 10° to 57° in laboratory system. The energy autocorrelation functions of the dissipative fragments have been analyzed by using different approaches,especially using the statistical nuclear reaction model with memory. The results indicate that the intermediate dinuclear system formed in the dissipative process is set in a damped coherent nuclear rotation which causes the nonself averaging oscillation structure in the excitation functions and originates from a typical quantum chaotic motion. 相似文献
14.
HUA Hui JIANG DongXing LI XiangQing QIAN Tao WU HeYu JIN GenMing ZHAN WenLong DUAN LiMin GUO ZhongYan XIAO ZhiGang LI ZuYu WANG ShuFang ZHANG BaoGuo 《中国物理C(英文版)》2000,24(6):512-517
In the reaction of 33.4MeV/u 17N on a target 9Be,the measured neutron spectra at different angles exhibit a complex pattern and vary regularly as a function of the detected angle. The detected neutrons probably come from the three origins:nucleon-nucleon collisions between the projectile and target,break-up of 17N and statistical evaporations from the hot nuclei. By analyzing the measured neutron angular distribution and calculating with QMD and GEMINI for the reaction concerned, 4.49,0.44 and 5.5barns were obtained for neutron emission cross sections due to the three origins mentioned above,respectively. 相似文献
15.
The cross sections of reactions 58Ni(n,2n)57Ni,58Ni(n,p)58mCo,58Ni(n,p)58gCo and 58Ni(n,p)58m+gCo were measured based on 27Al(n,a) 24Na reaction by activation methods.Incident neutron energies were 14.10MeV and 14.62MeV.A comparison was made between present results and other published data.The cross sections for 58gCo nuclei formation are given for the first time. 相似文献
16.
LIU Xin WANG You-Bao LI Zhi-Hong JIN Sun-Jun WANG Bao-Xiang LI Yun-Ju LI Er-Tao BAI Xi-Xiang GUO Bing SU Jun ZENG Sheng YAN Sheng-Quan LIAN Gang HUANG Wu-Zhen LIU Wei-Ping 《中国物理C(英文版)》2012,36(8):716-720
The angular distribution of 1H(6He,p)6He elastic scattering has been measured at Ec.m.=4.3 MeV by using a thick-target inverse kinematic method. The experimental differential cross sections are reproduced by the distorted-wave Born approximation calculation utilizing the CH89 global optical potential parameter set. The real part of CH89 is reduced comparing with other potentials, which may be attributed to the couplings necessary for the weakly bound nuclei. 相似文献
17.
Liu Zuhua Xu Jincheng Zhang Huanqiao Qian Xing Qiao Yu Lin Chengjian Xu Kan 《中国物理C(英文版)》1994,18(6):489-495
We have succeeded in isolating the complete arising from complete fusion-fission in terms of the fragment folding angle technique,and measured complete fusion-fission cross sections and fragment angular distributions for the 16O+232Th system in the center-of-mass energies between 72.61 and 80.11 MeV.The observed fission excitation function is in quite good agreement with the expectation of the coupled-channels theory.However,the measured fragment angular distributions are more anisotropic than the predictions of both the saddle-point transition-state model and scission model. 相似文献
18.
FENG En-Pu WANG Qi ZHU Yong-Tai YIN Xu MIAO He-Bin SUN Shu-Ming LI Song-Lin WU Zhong-Li FAN Guo-Ying XIE Yuan-Xiang ZHAN Wen-Long 《中国物理C(英文版)》1986,10(3):323-329
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
19.
WANG DA-YAN LI ZU-YU YUAN SHUANG-GUI GUO ZHONG-YAN JIN GEN-MING XU GUO-JUN YUE HAI-KUI WANG XI-MING CHEN JU-SHENG ZENG WEN-BING XIE HONG-MEI QIAN ZHENG-GUANG ZHANG LI DAI GUANG-XI 《中国物理C(英文版)》1982,6(5):609-615
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. 相似文献
20.
HAN Yin-Lu 《中国物理C(英文版)》2004,28(2):177-180
Based on the new measurements of total, nonelastic, elastic cross section and elastic scattering angular distributions for n+U reactions, a set of neutron optical model potential parameters is obtained in the region of incident neutron energy from 0.1 to 20 MeV. The cross sections, angular distributions, energy spectra and double differential cross sections are calculated and analyzed by optical model, nuclear fission theory, distorted wave Born approximation theory, coupled channel theory, the unified Hauser-Feshbach theory, as well as exciton model. The results indicate that our theoretical model can reasonably analysis n+ 238U reaction data with neutron energy lower than 20 MeV. 相似文献