19F+27Al耗散反应中双核系统的转动与形变

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. 从产物的 能量自关联函数中提取了反应中所形成的中间双核系统的转动惯量, 与相粘模型计算的刚体转动惯量相比较, 结果表明形成的双核系统有大的形变.     

19F+27Al深部非弹性碰撞产物的角分布

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.     

An Atomic Force Microscopy Investigation of the Tracks Made by C1^＋－C4^＋ Bombardment on CR－39 Detectors

Carbon micro-clusters are accelerated by an HI-13 tandem accelerator. The plastic nuclear track detectors CR-39are irradiated by C1-C4 beams from the HI-13 tandem accelerator and the tracks in CR-39 are studied using anatomic force microscope (AFM). The depths and diameters of C1-C4 tracks are measured for the first time in ananometre scale. An enhancement of the energy loss is obtained for carbon clusters related to single carbon ionswith the same velocity. The results show that the AFM observation is very useful in the quantitative analysis ofclusters in the track detector CR-39.     

Be~9(d,p),(d,t),(d,a)反应研究

本文在E_d=0.1—2.5MeV能量范围内,研究了Be~9(d,p_0)Be~(10)(0),Be~9(d,p_1)Be~(10)(3.368MeV),Be~9(d,t_0)Be~8(0),Be~9(d,α_0)Li~7(0)及Be~9(d,α_1)Li~7(0.478MeV)诸反应。在E_d=0.150,0.220,0.401,0.706,1.005,1.301,1.484,1.750,2.000,2.250和2.500MeV共十一个能量上分别测量了这五群出射粒子在θ_L=10—155°区间的角分布。在θ_L=135°,E_d=0.1—2.5MeV,在θ_L=95°,E_d=0.1—2.2MeV,和在θ_L=112.5°,E_d=0.5—2.5MeV测量了Be~9(d,p_0)Be~(10)的激发函数。在θ_L=135°和112.5°,E_d=1.2MeV,用较厚靶(100—300μg/cm~2)测量了Be~9(d,p_0)Be~(10)(0)反应的截面绝对值,结果为σ_p_0(θ_L=135°)=1.60mb/sr,σ_p_0(θ_L=112.5°)=1.55mb/sr。这样就得到了在此能区内,这五群出射粒子的截面情况。对所得结果进行了一些讨论。     

19F+51V耗散反应同位素类弹碎片的截面涨落

采用飞行时间(TOF)加△E-E探测系统,在102.25-109.50MeV(能量步长为250keV)的¹⁹T+⁵¹V反应中,第一次给出了耗散碰撞同位素产物的激发函数,讨论了双核系统的能量相干宽度Γ与产物的质量数A和Γ与产物的中子过剩自由度N/Z的依赖关系.     

96MeV 16O+64Ni反应机制的研究

在96MeV ¹⁶O离子轰击下,测量了¹⁶O+⁶⁴Ni反应出射碎片(α直至O元素)的Wilczynski图和角分布,并提出DIC截面和反应时间等物理量;讨论了反应的DIC特征;看到了出射碎片α和Li主要来源于复合核蒸发的迹象.     

表面高分辨弹性反冲探测分析

在中国原子能科学研究院 HI- 1 3串列加速器上建立了用 Q3D磁谱仪动量分析和ΔE- E粒子分辨对材料表面进行高分辨的弹性反冲探测分析技术 .用 1 0 0 Me V12 7I对 C/Li F多层样品的深度分布分析表明 ,表面分辨达到 1 .2 nm.所建立的ΔE(气体 ) - E(半导体 )望远镜探测器可同时分析从轻至中重的所有元素 .实测了新光电材料 Ga N,La2 Sr Cu O4 超导膜和新超硬材料 C3N4 (Si)等样品. High resolution depth profiling technique with elastic recoil detection analysis has been developed at the HI 13 tandem accelerator of CIAE. A depth resolution of 1.2 nm was achieved at the surface of the samples with the Q3D magnetic spectrometer and the focal plane detector. From light to medium heavy elements were simultaneous analyzed with a small Δ E E telescope. The method was applied to depth profile analysis of C/LiF multilayers, La 2SrCuO 4 superconductor and GaN foil samples.     

16O+94Zr和16O+116Sn的弹性散射角分布测量

用北京Q3D磁谱仪及其重离子焦面探测器系统测量了两个体系的14个弹性散射角分布,即¹⁶O+⁹⁴Zr体系在52,57,59,62,72,82和92MeV 7个能量点及¹⁶O+¹¹⁶Sn体系在57,59,62,67,72,82和92MeV 7个能量点的弹性散射角分布.用耦合道理论的ECIS计算程序拟合数据,初步观察到了“阈反常”现象.     

Cross-Correlation of Excitation Functions for Different Fragments and Different Scattering Angles in ^27Al（^19F,x）y Reactions

Excitation functions have been measured for different projectile-like fragments produced in ^27Al（^19F, x ）y reactions at incident energies from 110. 25 to 118. 75 Me V in 250 ke V steps. Strong cross section fluctuations of the excitation functions are observed. The cross-correlation coefficients of the excitation functions for different atomic number Z and for different scattering angle θcm 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.     

19F+93Nb耗散反应的相互作用时间

测量了¹⁹F+⁹³Nb耗散反应产物的激发函数与角分布.从角分布的斜率提取的该反应系统的平均寿命在对称性较大的入射系统中反映了系统中耗散产物的特征时间;通过能量自关联函数方法从激发函数提取的反应时间不论在对称的还是在非对称的入射系统中都反映了耗散产物的特征时间.能量自关联函数还可以给出双核系统的转动角速度以及表征转动阻尼的退相干宽度,更好地描述双核系统随时间的整个演化过程.