1991 Vol. 15, No. 2

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Study on KC1 Colorated Center Doped with Na+ Crystal by Positron Annihilation
HUANG Mao-Rong, GU Hua, WANG Yun-Yu, HE Yong-Shu, YANG Ju-Hua, LIN Jian-Ming, XU Cheng-Huang
1991, 15(2): 97-102.
The relation of the live times and S parameters with doped quantities of Na+ have been studied by positron annihilation method in pure,colourable and irradiant KC1 single crystals,The results show that the concentration of vacancies of KC1 doped with 800ppm Na+ is 4.24×1017/cm3.It is close to that of the pure KC1 crystal.The obvious F centers exist in the colorated crystal.The S parameters are mainly influenced by the external electrons of halide ions.Mechanism of annihilation of KC1 crystal doped with Na+ has been discussed.
Cosmic Ray Muon on the Altitude of 5500m Above the Sea Level
FAN Xiao-Ling, SU Shi, WANG Yi
1991, 15(2): 103-110.
215 blocks of K6,K7,K8 lead emulsion chambers on Mt.Kanbala are carefully scanned,and a total of 111 muon events are found with zenith angle M(=tgθ)>2.5.The energy of muon showers are determined by saddle-shape curves.The intensity of muon,the energy spectrum and the zenith angle distribution of muon showers on the altitude of 5500m above sea level are shown in the energy region Eμ>2TeV.Meanwhile the simulation calculation is done for the behaviour of muon inside the emulsion chamber,simulation results are basically in agreement with the experiment.
Constraint on the Parameter of Group By Two Order Transformation of Field Variable Being Equal to Zero in Non-Abelian
QIU Rong
1991, 15(2): 111-116.
A sufficient and necessary condition that two order transformation of field variable in non-abelian gauge field is equal to zero is derived.Two order transformation of both the parameter of Group and field variable of Fermi fields are necessarily equal to zero.
Coupling Constant in High Temperature QCD and Deconfinement Phase Transition
GAO Song, LI Jia-Rong
1991, 15(2): 117-122.
Finite temperature renormalization group equation is employed to investigate the effective coupling constant of QCD with respect to temperature.At high temperature,it is very small over the entire region of momentum,this leads to the property of deconfinement of QCD.
Source Density Distribution and Intensity Interferometry in High-Energy Heavy-Ion Collisions
LIU Yi-Ming, HUO Lei, JIANG Yu-Zhen, WANG Shan
1991, 15(2): 123-130.
The fitted spatial parameter from intensity interferometry relates to an average radius of the particle-emitting source.The mean-square radius 2> of the source can be estimated by the small relative momentum correlation function.More detailed information about the source density distribution can be inferred from the value of k=2>/2>.A study of central collisions of 1.8A GeV Ar+Pb at the at the bevalac streamer chamber shows that the data are consistent with an a prioriGaussian model for the density distribution at the present level of experimental accuracy.The average radius of the pion source in the reaction is deduced,and a possible picture to describe the expanding pion source is presented.
The Systematical Investigation of Intermittency in High Energy Heavy Ion Collisions
1991, 15(2): 131-139.
The intermittency of multiparticle production processes in high energies oxygen,silicon and sulphur induced emulsion and sulphur gold interactions are investigated systematically.It is found that in the pseudorapidity region 1~0.1,the EMU01 data exhabits the intermittent behaviour.The intermittent indexes are found to decreases with increasing the incident energy and mean multiplicity and to increase with increasing target mass.It seems also to increase as the projectile mass increases.
The Temperature Dependence of Giant Resonances in High-Excited Nucleus
LI Ming, SONG Hong-Qiu
1991, 15(2): 140-149.
We use the Hartree-Fock equation and the linear response theory in finite temperature to calculate the positions and transition strenghths of the giant resonances of high-excited nucleus Pb28.The result shows a downward shift and a broadening of the giant resonance energies as temperature increases.
Relation Between the Gap at Z=64 Subshell and the Abrupt Transition in the Region N=88~90
SANG Jian-Ping, LIU Chao-Shan, LIU Yong
1991, 15(2): 150-157.
The onset of deformation in the N=88~90 region and the effects of the gap at Z=64 subshell on nucler structure are investigated in a microscopic approach of the interacting boson model.It turns out that,besides the n-p interaction,the distribution of single particle levels in the shell model space also plays a direct and important role in the rapid transition of spectrum structure.For Nd~Dy nuclei the calculations show excellent agreement agreement with experimental energy systematics.
Study of the Reaction Mechanisms Induced by 16O on 64Ni at 96MeV
YAN De-Hong, GUO Zhong-Yan, WU En-Jiu, YIN Shu-Zhi, FAN En-Jie, XI Hong-Fei, LIU Guan-Hua, ZHANG Qing-Li, FENG En-Pu, LU Xiu-Qin, ZHAO Kui, CHENG Ye-Hao, LI Qing-Li, LI Min, JIANG Cheng-Lie
1991, 15(2): 158-164.
The angular distributions and Wilczynski plots of emitted fragments from He to O in reaction of 16O+64Ni at 96MeV have been measured.The DIC cross section and intereaction time were obtained.DIC character of the reaction was discussed.The trace which shows that the emitted fragments of He and Li mainly come from the evaporation process of compound nuclei emerged.
Measurement of Small-Angle Scattering of 14.7MeV Neutrons by C and Be Nuclei
WAN Dai-Rong, CAO Jian-Hua, DAI Yun-Sheng, LIANG Xue-Cai
1991, 15(2): 165-169.
The 14.7MeV neutron small-angle elastic scattering differential cross sections of C and Be are measured by a position-sensitive spectrometer with associated particle time-of-flight method.The corrections for neutron flux attenuation and multiple scattering are performed by using Monte-Carlo calculations.The experimental results are compared with the opticalmode calculation and other measurements.
The Decay of 120Ba
XU Shu-Wei, YUAN Shuang-Gui, GUO Jun-Sheng, LIU Man-Qing
1991, 15(2): 170-177.
120Ba was produced by 68MeV 16O beam bombarding a 2mg/cm2 thick 106Cd target and fluorated in a halium-jet ion source.The decay of on-line mass separated activity 120Ba has been studied by γ-X,γ-γ γ-β coincidence measurements.Its halflife was measured to be 24±2s.The total decay energy was extracted to be QEC=5.0±0.3MeV.A simple decay scheme has been proposed.
Vector Coherent State Representations of SO5 SU2 SU2 U1 U1 and SO5 U1 U1
PAN Feng
1991, 15(2): 178-186.
VCS representantions of SO5 SU2 SU2 U1 U1 and SO5 U1 U1 are discussed.Reduced matrix elements for SO5 SU2 SU2 are derived.The multiplicity of a weight for SO5 is determined by using the K-matrix technique.
A Possible Island of Beta-Delayed Neutron Precursors in Heavy Nucleus Region
1991, 15(2): 187-190.
The possible Beta-Delayed neutron precursors in the elements Tl,Hg,and Au were predicted following a systematic research for the known Beta-Delayed neutron precursors.The masses of the unknown nuclei and neutron emission probabilities were calculated.