共查询到20条相似文献,搜索用时 15 毫秒
1.
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
2.
The dynamical calculation of quasi-fission reaction induced by 10.6MeV/u 84Kr on 27Al is performed using one-body dissipation model.The calculation suggests a fission time larger than 200×10-22 sec.It is found that the threshold for emergence of quasi-fission in the reactoin system is 8MeV/u. 相似文献
3.
ZHANG Li JIN Gen-Ming ZHAO Jin-Hua YANG Wei-Fan YANG Yong-Feng ZHAO Zhi-Zheng ZHENG Ji-Wen SUN Xiu-Rong LI Zong-Wei QIN Zhi WANG Ji-Cheng GUO Guang-Hui 《中国物理C(英文版)》1992,16(8):767-768
The new neutron-rich isotope 208Hg has been identified for the first time from the reaction products in fully-stopping thick nat.Pb target bombarded by 30MeV/u 12C beam provided by the Heavy Ion Research Facility in Lanzhou.Assignment of the nuclide 208Hg was based on the measurements of the deacy γ energy and halflife of its daughter 208Ti,which was grown up with 208Hg β-deacy.The half-life of 208Hg β-deacy was determined to be 42+23-12 min.The average production cross section of 208Hg over the incident energy region from Coulomb barrier to 30MeV/u is found to be 1.1±0.5μb. 相似文献
4.
Temperatures and Excitation Energies of Hot Nuclei in Reactions of 40Ar+natAg,209Bi at MeV/u 下载免费PDF全文
Yin Shuzhi Jin Weiyang Zhang Chun Jin Genming Zheng Jiwen Wu Enjiu Tan Jilian Li Zuyu Wang Sufang Song Mingtao Wu Heyu He Zhiyong Jiang Dongxing Qian Xing 《中国物理C(英文版)》1997,21(8):680-685
Coincidence measurements of fission fragment and light charged particle have been perfotrmed for the reactions of 40Ar+natAg,209Bi at E/A=25MeV using 4 PPAC and 11 sets of ΔE-E telescopes.Angular correlations of fission fragment were ploted as a function of the folding angle between the two detected fission fragments.The linear momentum transfer distributions were derived by measuring angular correlations.The backward spectra of light particles detected in coincidence with fission fragments having different average〈LMT〉are analyzed with Maxwell distribution.After some corrections the initial temperatures of the hot nuclei are determined from the energy spectra.The excitation energies corresponding to the different average〈LMT〉are obtained considering the reaction Q values and pre-equilibrum emission.In the central collision of the 40Ar+natAg,209Bi reactions,excitation energies are measured to be about 4.2MeV/u,2.4MeV/u and temperatures about 6.1MeV,5.5MeV,respecdvely.In semi-central collision,excitaionen energies are measured to be about 3.5MeV/u,1.9MeV/u and temperatures about 5.8MeV,4.8MeV respectively. 相似文献
5.
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
6.
Isospin Effect on Relative State Population Temperature in the Reactions 40Ar+ 112,124Sn at 30MeV/u 下载免费PDF全文
HU Rong-Jiang WU He-Yu ZHU Yong-Tai JIN Gen-Ming DUAN Li-Min XIAO Zhi-Gang WANG Hong-Wei LI Zu-Yu WANG Su-Fang ZHANG Bao-Guo WEI Zhi-Yong LU Zhao-Hui ZHU Hai-Dong FENG Zhao-Qing YUAN Xiao-Hua 《中国物理C(英文版)》2004,28(2):152-157
An array of 13 detector telescopes has been used for detecting small-angle particle-particle correlations in the reactions 40Ar+112,124Sn at 30MeV/u. The α-α correlation functions were extracted from two-particle coincident events. A three-body trajectory code MENEKA was used to calculate the background correlation function. The detection efficiency was calculated by using the Monte-Carlo method. After subtracting the background correlation and making the detection efficiency correction, the temperatures of 4.18±0.25 0.21 MeV and 4.10±0.22 0.20MeV are obtained from relative populations of 8Be states for the reaction systems with different isospin,40Ar+112Sn and 40Ar+124Sn, respectively. From the relationship between the state population temperature and outgoing particle energies, it is found that the emission temperature decreases with increase of the particle energies for both studied reaction systems. For the neutron deficient system 40Ar+112Sn the emission temperature is 5.13±0.30 0.26MeV for the lower emitting particle energies and 3.87±0.37 0.29MeV for the higher emitting particle energies. And for the neutron rich system 40Ar+124Sn the emission temperature is 5.39±0.30 0.26MeV for the lower emitting particle energies and 3.32± 0.28 0.23MeV for the higher emitting particle energies. This kind of isospin dependence is discussed. 相似文献
7.
Azimuthal Distribution and Azimuthal Correlation of the Particles in 10.6MeV/u 84Kr+27Al Collision 下载免费PDF全文
The light charged particle emission in coincidence with fragmemts in 10.6MeV/u 84Kr+27Al collision is studied.Emphasis is laid on the characters of two-order anisotropy coefficient of Fourier expansion up to two order from fitting particle azimuthal distribution and particle-particle azimuthal correlation.The derived results prove that particle emission is statistically independent with the same azimuthal distribution in each event.It is found that two-order anisotropic coefficient depends weakly on the fragment mass and increases with increasing emitted particle mass. 相似文献
8.
Pan Qiangyan Yuan Shuanggui Yang Weifan Li Zongwei Ma Taotao Guo Junsheng Liu Mingyi Liu Hongye Xu Shuwei Gan Zaiguo Kong Dengming Qiao Jimin Luo Zihua Zhang Mutian Wang Shuhong 《中国物理C(英文版)》1999,23(11):1039-1043
230Pa was produced with the reaction 232TH (p, 3n)230Pa in the irradiation powder targets of ThO2 with 35 MeV Proton beam. Sources of 230Pa -230U were prepared by radiochemical method. Using solid-state track registration detectors, two events of 230U decay with heavy cluster emission have been observed. The preliminary branching ratio to decay comes out to be B=λNe/λα=(1.3±1.8)×10-14. 相似文献
9.
Isospin Effect on the Emission Mechanism of Hot Nuclei in 35MeV/u 40Ar +112Sn/124Sn Reactions 下载免费PDF全文
Wu Heyu Xiao Zhigang Li Zuyu Wang Hpmgweo Duan Limin Zhang Baoguo Liu Yongying Wang Sufang Jin Genming Xiao Guoqing Guo Zhongyan Zhu Yongtai 《中国物理C(英文版)》1999,23(11):1115-1118
As an extension of radioactive ion beam physics, the research on isospin dependent properties of hot nuclei has increasingly attracted considerable interest. The isospin effect on the decay of hot nuclei in reactions 35MeV/u 40Ar+112Sn/124Sn has been investigared. It is concluded that due to Coulomb repulsion and instability, proton-rich hot nuclei probably emit prides such as a with high energy to increase their neutron-proton ratio. Moreover, the decay chain for those particles is seemingly long and the emission Probability is high. Thus, the conventional observations, for instance, the ‘slope temperature’ extracted from energy spectrum, may very appreciably with the measured particles. 相似文献
10.
XIAO Zhi-Gang WU He-Yu LI Zu-Yu JIN Gen-Ming WANG Hong-Wei DUAN Li-Min ZHANG Bao-Guo HU Rong-Jiang WEI Zhi-Yong LIU Yong-Ying WANG Su-Fang LU Zhao-Hui ZHU Yong-Tai ZHU Hai-Dong 《中国物理C(英文版)》2001,25(6):494-499
Isotope ratios,defined as the yield ratio of two isotopes with the same charge,were analyzed as a function of kinetic energy of outgoing particles at 20° in the reactions of 40Ar+112,124Sn and 5°in36Ar+112,124Sn at incident energy of 35MeV/u. Isotope ratios between the neutron-deficient isotopes and stable isotope increase with kinetic energy,while those between the neutron rich isotopes and stable isotope decrease. This different behavior was observed similar for both 112Sn and 124Sn targets. The isotope ratios show rather obvious target dependence at 20° and little target dependence at 5°. As the outgoing energy getting down,the N/Z ratio of the fragmentation products at 5° diverts gradually from the N/Z ratio of the projectile to that of the system. These observations indicate that the isospin degree of freedom does not reach complete equilibrium in the peripheral or semi-peripheral collision at this bombarding energy. 相似文献
11.
High-spin states in 179Pt have been studied experimentally using the 149Sm(35Cl, p4n) fusion-evaporation reaction at beam energies of 164—180MeV. Measurements of γ-ray excitation function, X-γ coincidences and γ-γ-t coincidences were carried out with 13 BGO(AC) HPGe and 3 LOAX detectors. Based on the measured results, three rotational bands built on intrinsic states assigned to the 1/2-[521], 5/2-[512] and 7/2+[633] Nilsson configurations have been established for 179Pt. It has been observed that the aligned angular moment in the 1/2-[521] band increases suddenly around hω=0.27MeV. The big signature splitting has been observed in the 7/2+[633] band. These phenomena are discussed by referring to the systematics of the level structure in the Pt isotopes and isotones of 179Pt. 相似文献
12.
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
13.
Some experimental results measured for light emission particles with Z≤2 from 12C+64Ni reaction at E(12C)=69, 56MeV are reported. A comparison between moving source model calculation and proton's spectra have been performed. Extracted parameters of the source with faster velocity are agreement with the systematic values found before. The composite particle energy spectra of α, 3He and D were analyzed by coalescence model. 相似文献
14.
Emission Time Measurements of Light Particles from 40Ar+197Au Collisions in Intermediate Energies 下载免费PDF全文
He Zhiyong Duan Limin Li Zuyu Jin Genming Luo Qingzheng Wu Heyu Zhang Baoguo Wen Wanxin Qi Yujin Dang Bingrong Dai Guangxi 《中国物理C(英文版)》1996,20(1):8-12
Particle-particle correlation functions have been measured for 40Ar+197Au collisions at E=25 MeV/u.Emission time of light particles has been extracted from correlation functions using the three-body trajectory model.The average emission time varies with the energy of particles. It decreases from about 300 fm/c for low energy particles to about 100fm/c for energetic particles. 相似文献
15.
Under conditions near the center of the Sun, it shows that 7Be atoms are completely ionized between R=0 to R=0.1217R⊙. The newly calculated 7Be and 8B solar neutrino fluxes are about 4.00×109cm-2·s-1 and 6.18×106cm-2·s-1, while the corresponding predicted values of the standard solar model are 4.80×109cm-2·s-1 and 5.15×106cm-2·s-1,respectively. It will further increase the discrepancy between the observed and the predicted neutrino fluxes in Super Kamiokande neutrino experiment. 相似文献
16.
Study of in beam γ ray spectroscopy of 127I has been performed using 124Sn(7Li, 4n)127I reaction at 32 MeV beam energy. A new level scheme of 127I has been established including 25 new levels and 52 new γ transitions. Negative parity levels based on 11/2- π h11/2 particle state have been observed up to (35/2-) extending our knowledge of decoupled structures to the heavier iodine isotope. Two ΔI=2 yrast positive-parity levels have been proposed to be associated mainly with the πg7/2 configuration due to observations of several strong inter band transitions. Two weakly populated ΔI=2 positive parity levels and a high-lying ΔI=1 cascade have been newly identified and tentatively assigned as πd5/2 one-quasiparticle and three quasiparticle bands, respectively. 相似文献
17.
GAN Zai-Guo FAN Hong-Mei QIN Zhi WU Xiao-Lei GUO Jun-Sheng LEI Xiang-Guo DONG Cheng-Fu XU Hua-Gen CHEN Ruo-Fu ZHANG Fu-Ming GUO Bin LIU Hong-Ye WANG Hua-Lei 《中国物理C(英文版)》2004,28(4):332-334
New isotope 265Bh(Z=107) was produced in bombardment of an 243Am target with 135MeV 26Mg ions at HIRFL. Identification was made by observation of correlated α particle decays between the new isotope 265Bh and its 261Db and 257Lr daughters with four pairs of detectors. A total of 8 correlated decay events of 265Bh and 4 decay events of 264Bh were identified. 265Bh decays with a 0.94+0.70-0.31s half-life by emission of α particle with an average energy of (9.24±0.05)MeV. 相似文献
18.
The Cross Section Fluctuation of the Isotope Projectile-Like Fragments in the Dissipative Process of Reaction 19F+51V 下载免费PDF全文
Wang Qi Lu Jun Xu Hushan Li Songlin Zhu Yongtai Yin Xu Fan Enjie Zhang Yuhu Li Zhichang Zhao Kui Lu Xiuqin Hu Xiaoqing 《中国物理C(英文版)》1996,20(4):289-296
By using a detection system combining Time-of-Flight(TOF)method with(△E-E)technique,the excitation functions,the dependence of energy coherence widthΓon product mass A and the dependence of Γon the degree of freedom of neutron excess N/Z for some elements and their isotope products in the dissipative process of reaction 19F+51V at energies from 102.25MeV to 109.50 MeV(in 250 keV steps)were presented and discussed for the first time. 相似文献
19.
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
20.
ZHANG Yu-Hu 《中国物理C(英文版)》2002,26(6):582-588
High spin states in deformed odd-odd 180Ir have been investigated using the 154Sm (31P, 5nγ)180Ir reaction through the measurements of excitation functions at 150, 155, 160, 165 and 170 MeV beam energies, K X-γ and γ-γ coincidences at 160 MeV. A new level scheme composed of 5 rotational bands has been established. According to the band structure characteristics and the deduced in band B(M1)/B(E2) ratios, the quasiparticle configurations and spin and parity have been proposed to the observed bands. The neutron AB crossing is observed at hωc≈0.26 MeV for the π1/2-[541]⊙ν1/2-[521] and π1/2-[541]⊙ν5/2-[512] bands. This AB crossing frequency is close to that in the ν5/2-[512] band of 179Os indicating the loss of intruder nature of the π1/2 - orbit. Gradual alignment gain in both the π9/2-[514]⊙ν7/2+[633] and π9/2-ν5/2-[512] bands is observed which is similar to the low spin anomaly in alignment in the πh11/2,πd5/2 and πi13/2 bands of neighboring Ir and Re isotopes. Different alignment properties have been discussed in the framework of cranked shell model, and a larger quadrupole deformation is suggested for the bands with π9/2-[514] orbit involved. 相似文献