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关联函数在耗散反应激发函数涨落中的应用 总被引:1,自引:0,他引:1
应用关联函数方法,分析耗散反应激发函数中的涨落.通过推导出能量自关联函数、角度互关联函数、反应产物元素之间的互关联函数、反应产物同位素之间的互关联函数,来分析在耗散反应这一由非平衡向平衡演化的系统中,核反应体系演化过程的特点,说明关联函数在研究耗散反应激发函数涨落中的特殊作用.用推导出的函数分析了实验4.5MeV/u 27Al+27Al和102.5MeV
19F+51V的数据,并且指出了用这种方法可以提取的耗散反应体系的信息. 相似文献
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测量了19F+27Al耗散反应产物B,C,N,O,F和Ne的激发函数, 入射束流的能量从110.25MeV到118.75MeV,能量步长为250keV. 用能量自关联函数方法从激发函数中提取了各反应产物的平均衰变宽度, 利用同时考虑反应中所形成的中间双核系统的转动特性和衰变特性而发展了的Ericson核反应统计理论, 讨论了19F+27Al耗散反应中双核系统随时间的演化过程. 相似文献
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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
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重离子耗散反应产物激发函数研究的新进展 总被引:1,自引:1,他引:0
评述了近两年多来在重离子耗散反应激发函数研究中新的实验结果与理论进展.重点介绍27Al+2 7Al耗散反应产物的长程角度关联以及19F+93Nb耗散反应中截面及其涨落测量的不可重复性. The experimental study and the theoretical development on the structures of excitation functions in dissipative heavy ion collisions last years were reviewed. Especially the long range angular correlation in the reaction of 27Al+ 27Al and the non reproducibility of the cross sections measured in the reaction of 19F+ 93Nb were introduced. The experimental results indicate that the angular coherent width in the dissipative... 相似文献
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I. Weidl D. Evers P. Konrad K. E. G. Löbner U. Quade K. Rudolph S. J. Skorka 《Zeitschrift für Physik A Hadrons and Nuclei》1984,319(1):67-80
Selectively excited high-spin states in27Al have been located by the reaction12C(16O,p)27Al. The excitation functions of these states have been measured at incident energiesE cm=18.7 to 30.1 MeV at intervals of 150 keV. They exhibit maxima of presumably non-statistical origin. At four different energies the subsequent decay of the27Al states has been studied by detecting the final heavy recoils with the Munich recoil spectrometer in coincidence with the proton emitted in the first stage of the reaction. Using this new method branching ratios of theγ-, α-, andn-decay have been measured. Based on angular correlation arguments spins up to 27/2? have been determined within the experimental accuracy of 1–2?. The observations suggest a superdeformed shape of27Al at least in some of the states. 相似文献
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C. T. Coburn J. F. Shriner Jr. C. R. Westerfeldt 《Zeitschrift für Physik A Hadrons and Nuclei》1992,343(2):185-189
Angular distributions for27Al(p, α 0) and excitation functions for27Al(p, p 0) and27Al(p, α 0) have been measured for 2+ resonances in thep+27Al system. For 10 of these resonances, partial widths have been determined for three proton channels, and the relative sign between the reduced width amplitudes in two of these channels has been deduced. Linear correlation coefficients between reduced widths and between reduced width amplitudes in different channels have been calculated. The amplitudes appear consistent with the expected Gaussian distribution. 相似文献
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M. Lickert J. Brenneisen F. Glatz D. Grathwohl A. Martinez v. Remisowski H. Röpke J. Siefert B. H. Wildenthal 《Zeitschrift für Physik A Hadrons and Nuclei》1988,331(4):409-432
Gamma decay modes and spin assignments of levels in27Al have been investigated by proton-γ-ray angular correlation measurements in the24Mg(α, pγ) reaction at 14.2, 15 and 15.6 MeV bombarding energy and byγ-ray angular distribution measurements on the Ep=1820, 2114, 2293 and 2574 keV resonances of the26Mg(p, γ) reaction. Unique spin assignments were obtained as follows: I=3/2 for the 5827 keV state, I=5/2 for the 6115, 6465, 6765, 7577, 7721, 8097, 8136, 8324 keV states, I=7/2 for the 5433, 6533, 7413, 8037, 8442, 8586 keV states, I=9/2 for the 5418, 6512, 6713, 7997 keV states, I=11/2 for the 5500, 6948, 7400, 8396 keV states. The level scheme and electromagnetic properties of levels are compared with the results of shell model calculations which use the complete configuration space of the 0d5/2-1s1/2-0d3/2 shell and the unifieds-d shell Hamiltonian. The agreement is good to excellent and extends into the region of high level density above 7 MeV excitation energy. The total B(M1↑) below 8.5 MeV excitation energy is evaluated, using published resonance fluorescence and (e, e′) data, and quenching relative to the free-nucleon predictions is reexamined. Evidence in favour of a prolate ground state deformation of27Al and implications of this work for the astrophysically interesting26Al(p, γ) reaction are discussed. 相似文献
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G Engelhardt H Koller P Sieger W Depmeier A Samoson 《Solid state nuclear magnetic resonance》1992,1(3):127-135
The 27Al NMR spectra of calcium tungstate aluminate sodalite (CAW), Ca8[Al12O24](WO4)2, and the 23Na NMR spectra of sodium aluminosilicate sodalites of general composition Na9[Si6Al6O24]A2 with A = B(OH)4- (SBS), SCN- (SRS) and A2 = SO4(2-) (SSS), MoO4(2-) (SMS) have been measured using magic-angle spinning (MAS) and double-rotation (DOR) techniques. Rotor synchronized pulse excitation is applied in the DOR experiments. Dramatic line narrowing is observed in the DOR spectra of all samples. The 27Al DOR NMR spectra of CAW measured at 9.4 and 11.7 T and spinning rates of 800-1150 Hz of the outer and 5 kHz of the inner rotor show seven sharp central lines accompanied by a manifold of spinning sidebands. These lines correspond to the seven crystallographically inequivalent Al sites of the CAW framework derived from X-ray structure analysis. From the difference of the line positions in the 9.4 and 11.7 T spectra the quadrupole coupling constant, QCC, quadrupole induced shift, sigma qs, and isotropic chemical shift, delta cs, of each Al site have been calculated. QCC values in the range of 5 to 9 MHz are obtained which reflect the strong tetragonal distortion of the AlO4 tetrahedra in CAW. delta cs shows only small changes in the range between 74.4 and 77.2 ppm. A tentative assignment of all lines to the distinct Al sites is derived from the correlation between QCC and a "shear strain parameter" describing quantitatively the distortion of the AlO4 tetrahedra.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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Interaction time ~4.3×10-21s of the dissipative products in the collision 27Al+27Al is extracted from the measurement of excitation functions by using the developed Ericson statistical theory. 相似文献
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Ghetti R Helgesson J Avdeichikov V Golubev P Jakobsson B Colonna N Tagliente G Kopecky S Kravchuk VL Wilschut HW Anderson EW Nadel-Turonski P Westerberg L Bellini V Sperduto ML Sutera C 《Physical review letters》2003,91(9):092701
The emission time chronology of neutrons, protons, and deuterons from the E/A=61 MeV 36Ar+27Al reaction is deduced from two-particle correlation functions. 相似文献