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1.
Excitation functions are measured for different charge products of the ^19F+^27AI reaction in the laboratory energy range 110.25-118.75MeV in steps of 250keV at θlab=57°,31° and -29°. The coherence rotation angular velocities of the intermediate dinuclear systems formed in the reaction are extracted from the cross section energy autocorrelation functions. Compared the angular velocity extracted from the experimental data with the ones deduced from the sticking limit, it is indicated that a larger deformation of the intermediate dinuclear system exists. 相似文献
2.
Two independent measurements of cross sections for the ^19F ^93Nb dissipative heavy ion collisions have been performed at incident energies from 100 to 108MeV in steps of 250keV.In the two measurements,two independently prepared targets were used.All other experimental conditions were identical in both experiments.The data indicate that non-reproducibility of the non-self-averaging oscillation is yielded in the two measurements.This supports the recent theoretical predictions of spontaneous coherence,slow phase randomization and extreme sensitivity in highly excited complex quantum systems. 相似文献
3.
韩建龙 王琦 白真 董玉川 李松林 段利敏 徐瑚珊 徐华根 陈若富 吴和宇 李志常 路秀琴 赵葵 周平 刘建成 许国基 Sergey Yu Kun 《原子核物理评论》2008,25(4):322-326
在中国原子能科学研究院的HI 13串列静电加速器上完成了19F+27Al耗散反应产物的激发函数测量。 束流19F的入射能量从110.25 MeV到118.75 MeV, 步长250 keV, 测量了实验室系+57°, +31°, -15°和-29°出射的类弹产物B, C, N, O, F和Ne的激发函数。 观测到激发函数具有耗散反应的特征涨落结构, 分析了激发函数之间的长程角度关联以及强烈的电荷数关联。 Excitation functions have been measured for the projectile like fragments of B, C, N, O, F and Ne in the 27Al(19F,x)y reactions at incident energies from 110.25 MeV to 118.75 MeV in 250 keV steps. Strong cross section fluctuations in the excitation functions has been observed. The cross correlation coefficients of the excitation functions for different atomic number Z and for different scattering angle θ cm have been deduced. These coefficients are much larger than the statistical theoretical calculated ones. This indicates that there are strong correlations between different exit channels in the dissipative heavy ion collision of 27Al(19F, x)y. 相似文献
4.
A formula used to subtract the effect of gamma-ray of the others to that of measured reaction in measurement of cross section of nuclear reaction and its application
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ZHOU Feng-Qun YANG Xing-Qiang WANG Wei-Feng LI Yong ZHANG Fang TUO Fei KONG Xiang-Zhong 《中国物理C(英文版)》2008,32(11):873-876
Abstract According to the regulation of growing and decay of artificial radioactive nuclide, a formula used to subtract the effect of characteristic γ-ray of the others to that of measured reaction was deduced. And then the cross sections of 120Te (n, 2n)119mTe reaction induced by neutrons around 14 MeV were measured by activation relative to the 93Nb (n, 2n)92mNb. In the process of the cross sections measured to be calculated, it was subtracted that the effect of characteristic γ-ray of 126Te (n, p)126Sb to that of measured 120Te (n, 2n)119mTe reaction using the formula deduced. The experimental results were (689±37) and (750±41) mb at the neutron energies of (13.5±0.3) and (14.6±0.3) MeV, respectively. Measurements were carried out by γ-detection using a coaxial HPGe detector. As samples, spectroscopically pure tellurium powder has been used. The fast neutrons were produced by the T(d, n)4He reaction. The neutron energies in these measurements were determined by the method of cross-section ratios between 90Zr (n, 2n) 89m+gZr and 93Nb (n, 2n) 92mNb reactions. 相似文献
5.
完成了19F+27Al深部非弹性碰撞产物的角分布测量.初步分析了反应产B,C,N,O,F,Ne,Na,Mg和Al的实验室系角分布,展现出深部非弹性反应机制的特点,显示了反应系统随时间的演化过程. Angular distributions of fragments produced in the deep inelastic collision of~(19)F+~(27)Al have been measured for incident energy of 114 MeV at θ_(lab)= 9~(o), 24~(o), 40~(o), 55~(o), 70~(o) and 85~(o). Angular distributions of dissipative products B, C, N, O, F, Ne, Na, Mg and Al are analyzed to provide an evolution process of the intermediate dinuclear system formed in the reaction. 相似文献
6.
重离子核反应中的碎片发射机制是近年来人们十分关注的研究课题。利用ΔE-E 探测器,测量了~6 MeV/u 的19F+27Al 反应中核电荷数Z = 2 ~13 的出射碎片。对产物的能谱、角分布、激发函数及能量自关联函数的分析表明,出射产物主要来自弹靶核深部非弹性碰撞所形成的转动的双核系统。In recent years, extensive studies have been made to understand the fragment emission mechanisms in low energy light heavy-ion reactions. These fragments are found to be emitted from quasielastic/projectile breakup, deep-inelastic and fusion-fission processes. Fragments of Z = 2~13 induced by the collision of 19F+27Al have been measured by ΔE-E telescope. The analysis of the energy spectra, angular distributions, excitation functions and energy auto-correlation functions of these fragments shows that the emission of fragments is coming from a rotational dinuclear system formed in the dissipative collision of the projectile and target nuclei. 相似文献
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DongYuchuan WangQi LiSonglin DuanLimin WuHeyu XuHuagen ChenRuofu LiZhichang LuXiuqin ZhaoKui Zhouping LiuJiancheng 《近代物理研究所和兰州重离子加速器实验室年报》2003,(1):34-34
The measurement of excitation functions for the strongly dissipative collision with the reaction system of ^19F ^27Al has been carried out at the China Institute of Atoraic Energy, Beijing. The ^19F^8 beam was extracted from the HI-13 tandem accelerator. The beam incident energies were varied from 110 to 118.75 MeV in steps of 250 keV. The self-supporting ^27A1 target foil with the thickness of 60μg/cm^2 was used. The detector arrangement is shown in Fig.1. 相似文献
8.
王佳叶沿林 江栋兴张高龙庞丹阳 李智焕郑涛李湘庆 王全进胡青元 吴翠娥A.Ozawa Y.Yamaguchi R.Kanungo D.Fang I.Tanihata 《中国物理快报》2005,22(6):1370-1373
The breakup reaction cross sections were measured for the reaction of^6He at 25 MeV/nucleon from ^9Be target with intensity of 10^5 pps. By fitting the energy spectra of breakup α particles with Gaussian functions, the angular distribution of differential cross sections in the laboratory system has been extracted and compared with the Serber model calculations. The good agreement between the calculation and the experimental data favours a dominant configuration of the ^4He core plus valence neutrons for the structure of^6He. 相似文献
9.
HAN Yin-Lu GUO Hai-Rui ZHANG Yue ZHANG Jing-Shang 《理论物理通讯》2008,50(8):463-467
Based on the theoretical models for light nuclei, the calculations of reaction cross sections and the angular distributions for d +^8Li reaction are performed. Since all of the particle emissions are from the compound nucleus to the discrete levels, the angular momentum coupling effect in pre-equilibrium mechanism is taken into account. The three- body break-up process and the recoil effect are involved. The theoretical calculated results are compared to existing experimental data. 相似文献
10.
An electrostatic deflector for separating the fusion evaporation residues from the beam-like products in heavy ion reactions was installed. The evaporation residue separation and identification with the electrostatic deflector setup was tested with the reaction ^32S+^96Zr at several energies. The fusion evaporation residues and the beam-like particles were well separated after the electrical separation and the experimental fusion cross section obtained from the angular distribution is in good agreement with the calculated value well above the Coulomb barrier. This confirms the reliability of the setup. 相似文献
11.
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
12.
完成了19F+93Nb耗散反应产物激发函数的两次独立测量,入射束流的能量从102MeV到108MeV,步长250keV.实验结果在一些相同能量点两次测量的截面不能重复.分析表明:能量自关联函数的离散程度大约相当于随机计数率引起的离散程度的3倍;激发函数曲线相对于能量平均本底的几率分布,有大约21髎超出了标准高斯分布宽度的3倍;两次测量得到的截面之差的几率分布大约有18髎也超出了标准高斯分布宽度的3倍.可见,两次测量的19F+93Nb耗散反应产物激发函数的截面不重复性具有明确的统计意义,其来源不是计数率的随机涨落. 相似文献
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Non-reproducibility of the Cross Sections Measured in the Dissipative Collisions of 19F+93Nb
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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
16.
Non-Reproducibility of the Cross Sections of the Products Induced from Dissipative Reaction of 17F+27Al
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HAN Jian-Long WANG Qi DONG Yu-Chuan LI Song-Lin DUAN Li-Min WU He-Yu XU Hua-Gen CHEN Ruo-Fu XU Hu-Shan BAI Zhen LI Zhi-Chang LU Xiu-Qin ZHAO Kui 《中国物理C(英文版)》2006,30(2):108-112
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. 相似文献
17.
Measurement of Excitation Function and Analysis of StatisticalProperty in 27Al+27Al mssipative Reaction
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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
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G. Cardella M. Papa G. Pappalardo F. Rizzo Q. Wang A. De Rosa E. Fioretto G. Inglima M. Romoli M. Sandoli R. Setola L. Corradi G. Montagnoli D. R. Napoli A. M. Stefanini 《Zeitschrift für Physik A Hadrons and Nuclei》1990,336(4):387-390
Coherence energies extracted from excitation functions and angular distributions for the fragments emitted in the19F+63Cu reaction, measured in the range θlab=10° to 120° at incident energies between 100 to 108 MeV (lab.), were compared to the Kun model of dissipative collisions. An overall agreement was found for the angular distributions at forward angles. The general behavior of coherence energies was also properly described and interaction times were deduced. 相似文献