共查询到20条相似文献,搜索用时 281 毫秒
1.
YIN Xinmin LUO Qingzheng LI Wenxin ZHAO Lili SUN Rulin SUN Tongyu WU Dingqing 《中国物理C(英文版)》1993,17(11):979-984
The cross section is measured for 65 target residues produced from the interaction of indium with 42MeV/nucleon 12C ions using nuclear chemistry techniques.The experimental mass yield distribution gives a satisfactory agreement with that calculated from Monte Carlo code GEMINI based on the statistical binary decay model. According to the systematics of isotope distributions,the possibility of the production of new neutron-deficient nuclides far from β stability is discussed in the intermediate energy heavy ion reaction. 相似文献
2.
LI Wen-Xin SUN Tong-Yu QI Da-Hai SUN Ru-Lin SA Ben-Hao WU Ding-Qing ZHAO Li-Li JIN Gen-Ming 《中国物理C(英文版)》1990,14(8):745-752
Cross sections and average forward ranges were determined for 35 target residues from the interaction of copper with 44MeV/A12C ions with nuclear chemistry techniques.From these data the isobaric yield distribution,the mass yield distribution and the longitudinal momentum transfer were obtained.The mass yield distribution and the isobaric yield distribution are in good agreement with those calculated from a modified statistical model and corresponding Monte Carlo technique. 相似文献
3.
LI Wen-Xin SUN Tong-Yu WU Ding-Qing JIN Gen-Ming SUN Ru-Lin LI Yun-Sheng ZHAO Li-Li WANG Su-Fang 《中国物理C(英文版)》1991,15(4):329-335
The excitation functions,angular distributions and differential range distributions have been measured for target residues from the reaction of 65Cu induced by 45—96MeV 16O ions with radiochemical techniques.A comparison of the experimental data with Monte-Carlo simulations based on the statistcal model of compound nucleus that the heavy residues are produced by the decay of a compound nucleus formed by complete fusion.Incomplete fusion or massive transfer are the main reaction mechnisms leading to production of the residues with mass number close to that of the target. 相似文献
4.
135MeV/u 12C和铁相互作用中靶余核的质量分布 总被引:1,自引:1,他引:0
用核化学技术测定了135MeV/u 12C和铁相互作用中的靶余核的生成截面,通过高斯电荷分布函数得到了靶余核的质量分布.与46MeV/u 12C+Cu相比,发现A<30质量区的产额明显增加,且产物有偏向丰中子一侧的趋势.实验测定的质量分布与熔合碎裂模型和级联两体模型的计算结果进行了比较,结果似乎表明在很高入射能情况下多重碎裂衰变是A<30靶余核生成的主要反应机制. 相似文献
5.
Yin Xinmin Li Wenxin Zhang Xiang Sun Tongyu Shizuko Ambe Yoshitaka Ohkubo Masako Iwamoto Yoshio Kobayashi Fumitoshi Ambe 《中国物理C(英文版)》1995,19(11):991-997
Cross Sections and average forward recoil range FW were measured for target residues from the interaction of Cu with 40MeV/u 40Ar ions using off-line y-ray spectroscopy.The mass yield distribution was obtained with assumption of charge distribution.The linear momentum transfer was calculated from FW values.A comparison with similar results of 12C+Cu and 20Ne+Cu reactions indicates that the fractional linear momentum transfer,corresponding to central collisions,decreases with increasing projectile mass at the same energy per nucleon. However,the excitation energy of the composite system created from the collisions of Cu with 40Ar ions reached the value of 5.3MeV /u and was higher than those from the collisions with 12C and 20Ne ions. 相似文献
6.
XU Shuwei PAN Qiangyan ZHANG Tianmei YUAN Shuanggui ZHANG Xueqian SHI Shuanghui TIAN Jiaqi HUANG Wenda 《中国物理C(英文版)》1993,17(11):985-987
Activities of 183Os were produced by 39MeV α particles bombarding on a natural tungsten target.β+ spectrum with coincidence gate set on the strongest 382keV γ-rays of 183Os decay was measured.The endpoint energy of the β+ spectrum was determined and the QEC value of 183Os decay was extracted to be 2.24±0.10MeV which is in good agreement with the predicted value 2.30±0.10MeV on the basis of mass systematics. 相似文献
7.
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. 相似文献
8.
LI WEN-XIN SUN TONG-YU SUN XIU-BUA ZHANG TIAN-MEI ZHENG MAN-JIAO DONG TIAN-RONG FU MING 《中国物理C(英文版)》1982,6(3):365-372
Independent yields of 82Br, 96Nb, 112Ag, 130I,132I, 134I, 134mCs, 135mCs, 136Cs and upper limitof independent yield for 140La in the fission of 232Th induced by neutrons of 14 MeVwere determined with nuclear chemistry techniques. The correlation of the fractionalindependent yields in the high yield mass chains with a Gaussian curve of charge dis-tribution has been investigated using various mass formulae and charge distributionhypotheses. The results indicate that the hrpothesis of minimum potential energy witha shell-effected mass equation gives the best fit to the data. The width parameter Cof the charge distribution is found to be 0.80. The large deviations of 32Br and 112Ag from the Gaussian curve seem to show that the low yield in very asymmetric fissioncan be attributed to a narrower width of charge distribution, whereas the high yield insymmetric fission may correlate with a wider width. The trends have been explainedqualitatively in terms of a liquid drop model. There is no evidence for 40-proton subshell effect on the fission yield. 相似文献
9.
Isotope Ratios of Light Charged Particles and Temperature in the Reactions 30MeV/u40Ar+112,124Sn 下载免费PDF全文
XIAO Zhi-Gang WU He-Yu JIN Gen-Ming WANG Hong-Wei HU Rong-Jiang LIU Yong-Ying LI Zu-Yu DUAN Li-Min ZHANG Bao-Guo WEI Zhi-Yong WANG Su-Fang ZHU Yong-Tai ZHU Hai-Dong LU Zhao-Hui 《中国物理C(英文版)》2001,25(11):1071-1076
Coincidence measurements between residues and light charged particles (LCPs) have been made for the reactions 30MeV/u 40Ar+112,124Sn. The LCPs were measured by 11 semi-conduct telescopes from very forward angle to backward angle. The times of flight of the residues were measured by PPACs installed concentrically around the beam at forward angle. The excitation energy of the primary hot nuclei was obtained from the velocity of residues in the frame of incomplete fusion model. The single isotope ratios, as function of observing angle and excitation energy have been studied. The ratio of 3He/4He and 6Li/7Li increases with angle while that of 6He/4He and 8Li/7Li decreases. The calculation of statistical theory can not reproduce the curve quantitatively, implying the existence of dynamic effect. Isospin effect of the primary hot nuclei on the single isotopic ratios is demonstrated. However, the temperature extracted from double isotope ratios is target independent. 相似文献
10.
The Angular Distributions of intermediate Mass Fragments Emittsd in 30 MeV/u 40Ar+58,64Ni and 115In Reactions 下载免费PDF全文
Gou Quanbu Zhu Yongtai Xu Hushan Wei Zhiyong Lu Jun Zhang Yuhu Wang Qi Li Songlin Wu Zhongli 《中国物理C(英文版)》1999,23(4):328-333
The angular distributions of intermediate mass fragments with Z=3-19 emitted in 30 MeV/u 40Ar+58,64Ni and 115In reactions over an angular range of 5°—140°have been measured.Exponential distribution function: dσ/dΩ=N·exp(-θ/a) was used tO fit the measured angular distributions.We have extracted the decay factor a that can be connected with the interaction time τ, and the factor N that is related to the intensity of the emission source.The relationships of a(Z) with Z and N(Z) with Z for different reaction systems and different angular ranges have been discussed. The dependence of angular distributions on isospin and the symmetry of reaction system have also been discussed. 相似文献
11.
Energy Correlations between Fragments and Light Charged Particles in Reaction of 25MeV/u 40Ar+115In 下载免费PDF全文
WANG Jin-Chuan ZHAN Wen-Long GUO Zhong-Yan XI Hong-Fei ZHOU Jian-Qun ZHAO You-Xiong 《中国物理C(英文版)》2001,25(2):115-120
The correlations between the emitted fragments at θlab=15°and the light charged particles(LCPs) at the close geometry configuration in the reaction of 25MeV/u 40Ar+115In were measured. The energy correlations between fragments (4≤Zf≤14) and the LCPs including proton, deuterium, tritium and a particle as well as the energy spectra of the LCPs were obtained. The result shows the existence of sequential decay mechanism. It is found that the peak position of angular correlation is at the small angles and the most probable correlation angle is at 2°or so; The peak positions of the two components in the energy spectra of LCPs increase gradually with the mass of correlated partner; The lighter primaly products are more easier to be excited and decay to IMFs and the LCPs. In the Sequential decay, the yield of the LCPs with more heavier mass is higher than that of the lighter LCPs. The result reveals that the total correlation yield ratios summed over the fragments of Zf=4—14 are 1: 1. 3: 1. 78: 7. 57 for proton, deuterium, tritium and a particles, respectively. 相似文献
12.
J.P. Dufour H. Delagrange R. Del Moral A. Fleury F. Hubert Y. Llabador M.B. Hauhourat K.H. Schmidt A. Lleres 《Nuclear Physics A》1982,387(1):157-175
Cross sections, mean recoil ranges and angular distributions of radioactive a emitters produced in 12C, induced reactions at 1 GeV on medium and heavy targets are presented. A new on-line electrostatic collection device is used. A wide spectrum of heavy residues corresponding to various mass losses away from the target between D to 60 a.m.u. has been observed. A phenomenological analysis based on the statistical decay of possible precursors gives some information on the properties of the primary interaction. Losses of 10 to 30 nucleons can be partly fitted by the intranuclear cascade model. For greater mass losses, more collective primary interaction is needed. The abrasion-ablation model can produce such residues but in its clean cuts approximation the predicted excitation energy is too low. 相似文献
13.
Zhang Xueqian Yuan Shuanggui Yang Weifan Mou Wantong Yu Xian Li Zongwei Guo Tianrui Du Yifei Luo Yixiao 《中国物理C(英文版)》1996,20(8):673-677
The 175Er activity was produced via the reaction 176Yb(n,2p) 175Er by 14MeV neutron irradiation of a natural ytterbium metal target with a thickness of~80mg/cm2.X-γ and γ-γ coincidence measurements were employed to identify 175Er activity.The half-life of 175Er has been determined to be (1.2±0.3)min. Eight new gamma rays were assigned to the decay of 175Er. A partial decay scheme of 175Er has been proposed for the first time, from which a ground rotational band has been assigned to 175Tm. 相似文献
14.
Produchon yields were determined for 25 abet fragments produced from the reaction of iron with 80 MeV/u 16O ions. From these data, charge distribution and mass yield distribution have been deduced. The experimental results are compared with those reported from our previous work. It is found that the width parameter σz and the most probable charge Zp of the charge distribution increase slowly with increasing bombarding energy. The mass yield distribution is discussed in terms of the concepts of limiting fragmentation and factorization. 相似文献
15.
WU He-Yu DAI Guang-Xi CAI Wei QI Yu-Jin YAN De-Hong ZHANG Bao-Guo DANG Bing-Rong LUO Qin-Zheng QIAN Xing WEN Wan-Xin 《中国物理C(英文版)》1993,17(8):680-684
Alternative layers of target material,which were prepared by evaporating 209Bi on the surface of mica foils,were irradiated with 12C ions.Ternary fission events in which three fragments of comparable mass were produced in 2525-47.5MeV/A 12C+209Bi reaction,were recorded by the mica detectors with 2π geometry.The observed probability ratio of ternary fission relative to binary fission in 2π geometry was modified to 4π geometry spatial in terms of the Monte Carlo method.The values of ratioes increase with the bombarding energy,and are compared with the calculation result of the cascade fission model. 相似文献
16.
The pseudorapidity distribution of shower particles produced in the 24Mg-emulsion collisions at 4.5A GeV/c is reported in this paper. The dependences of the distribution width and the peak position on the target size are observed.The pseudorapidity distribution of shower particles for the events with low target multiplicity (light target) is narrower than that with high target multiplicity (heavy target). The maximum probability pseudorapidity for light target is greater than that for heavy target. The experimental data is analyzed by using the cylinder model suggested by Liu et al. The Monte Carlo results based on Liu's cylinder model are approximately in agreement with the experimental tendency and fluctuation. 相似文献
17.
Zhou Xiaohong Sun Xiangfu Guo Yingxiang Lei Xiangguo Liu Zhong Chen Xinfeng Zhang Yuhu Jin Hanjuan Luo Yixiao Wen Shuxian Yuan Guanjun Li Guangsheng Yang Chunxiang 《中国物理C(英文版)》1995,19(11):961-967
High-spin states in 197Bi were populated by bombarding natural Re target and isotope 187Re target with 16O beam of 100 MeV. Using comprehensive γ-γ-t coincidence measurements,three new isomers in 197Bi were established and eleven new y-transitions were identified,while errors in the existing level scheme were corrected.From the level structure systematics of the odd-mass Bi isotopes, the configuration and decay properties of a new isomer with t1/2n=19.3±4.9ns in 197Bi were discussed.The y-ray angular distributions were also measured.A new level scheme of 197Bi was proposed. 相似文献
18.
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
19.
Angular distributions and differential range distributions have been measured with nuclear chemistry techniques for 20 target residues from the reactions of 115In with 92 and 71MeV 16O ions.In terms of the increase of impact parameter,the results indicate continuous evolution of the reaction mechanisms from complete fusion,incomplete fusion to direct reaction involving steadily decreasing transfer of mass and momentum.Contribution of incomplete fusion in 16O+115In reaction is significantly larger than that in 16O+65Cu reaction. 相似文献
20.
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