Knockout Reaction Mechanism for ~6He~+

A knockout reaction experiment was carried out by using the 6He beam at 82.5 MeV/nucleon impinging on CH2 and C targets. The a core fragments at forward angles were detected in coincidence with the recoiled protons at larger angles. From this exclusive measurement the valence nucleon knockout mechanism and the core knockout mechanism are separated. This study provides a basis for the exclusive spectroscopic investigation of the exotic nuclei.     

~2H(~6He,~7Li)n反应角分布和~7Li的质子谱因子

在中国原子能科学研究院HI-13串列加速器次级束流线上,使用6He次级束首次测量了质心系能量为9.1 MeV的2H(6He,7Li)n反应角分布,并用扭曲波波恩近似(DWBA)进行理论分析,导出了7Li的质子谱因子为0.40±0.02。     

Measurement of One Proton Transfer Reaction ~(208)Pb(~7Li,~6He)~(209)Bi in Deep Sub-barrier Region

<正>Due to the limit of the intensity and quality of the radioactive ion beam(RIB),it is a difficult task to extract the optical model potentials(OMPs)of halo nuclear systems directly from the elastic scattering measurement.In view of this fact,the transfer reaction was tried to be used as an alternative method to extract and stud-     

Search for the Halo Effect in the ~1H(~6He,~6Li)n Reaction

The experiment is carried out using the secondary beam facility of the HI-13 tandem accelerator at China Institute of Atomic Energy, Beijing. The experimental setup is similar to the previously illustrated. A 7Li beam with energy of 44 MeV from the tandem impinged on a D2 gas cell at pressure of 1.5×105 Pa, in which 6He ions are produced via 2H(7Li, 6He)3He reaction. The front and rear     

Differential Cross Section Measurement for ~6Li(n,t)~4He Reaction at 3.67 and 4.42 MeV

Using a gridded ionization chamber, the differential cross sections for ~6Li(n,t)~4He reaction were measured at 3.67 and 4.42 MeV. The neutrons were produced with D(d,n)~3He reaction. Absolute neutron flux was determined through ~(238)U(n,f) and H(n,p) reaction. The result at 3.67 MeV is almost 90 degree symmetry but it is obviously forward peaked at 4.42 MeV in the center of mass system.     

Development of ~3He Neutron Detector Array for Measurement of (n,2n) Reaction Cross Section

<正>In the(n,2n)reaction cross section measurement,activation method is usually used.The advantage of this method is simple.When the product nucleus satisfies certain conditions,high accuracy measurement can be achieved.But when the activity of product nucleus cannot be accurately measured,the activation method is not applicable.In order to make up for the deficiency     

小型高分辨率^3He／^4He质谱计的离子光学

一、前言地球上氦同位素组成有三个层次:地幔氦、地壳氦和大气氦。地幔氦是地球生成时保留下来的原生氦,~3He含量高,~3He/~4He比值约10~(-5);地壳氦是地壳中铀、钍等放射性元素蜕变过程中生成的,~3He/~4He比值约10~(-7)～10~(-8);大气氦是在地幔氦与地壳氦不断地向     

Calculation of Proton Induced Reaction on ~(209)Biin Energy Region from 7 to 250MeV

Accelerator-drivencleannuclearenergysystem(ADS)researchisofinteresttomanycountries.AnimportantpartofADSisthehigh-intensityneutronsouce,whichconsistsofaleadorlead-bismuthtargetirradiatedbyprotonatmediumenergies.Inthisenergyregion,residualnucleicanbeproduce…     

Calculation of Proton Induced Reaction on ~(209)Bi in Energy Region from 7 to 250 MeV

Cross sections of p ~(209)Bi reaction are calculated from 7 to 250 MeV based on various nuclear reaction models, i.e., the optical model, evaporation model, exciton model, as well as direct reaction process. The comparison of the calculated results with the experimental data shows that our calculations are quite reasonable. Simultaneously, excitation functions of some long-lived radioactive nuclei and neutron multiplicity are predicted.     

Measurement of ~7Be(d,~3He)~6Li Angular Distribution

正The baryon density can be deduced from the Wilkinson microwave anisotropy probe(WMAP),and the ~6Li and ~7Li abundance can then be computed by the standard Big Bang nucleosynthesis model~([1]).Surprisingly,the primordial ~7Li abundances of astronomical observations are only     

Experimental Study for Near-barrier Reaction of ~7Be+~(209) Bi

<正>The radioactive beam physics in one of the current frontiers in nuclear physics.The reaction mechanism in the exotic-beam induced reactions is a hot topic.Considering this,the experimental study for the reaction mechanism of the nearbarrier~7Be+~(209)Bi reaction based on the radioactive-beam line RIBLL1 were performed in the Institute of Modern Physics (IMP) in Lanzhou.     

Optical Potentials of Halo System ~6He+~(64)Zn

正The angular distributions of the transfer reactions of ~(63)Cu(~7Li,~6He)~(64)Zn were measured at energies around the Coulomb barrier,to extract and study the optical model potential(OMP)of halo system ~6He+~(64)Zn in the exit channel.Due to the limit of the intensity and quality of the radioactive ion beam(RIB),it is a difficult task to     

Measurement of ~(25)Mg(~7Li,~6He)~(26)Al Angular Distribution

<正>In order to study the 58keV resonance in ~(25)Mg(p,γ)~(26)Al reaction,the measurement of the~(25)Mg(~7Li,~6 He)~(26) Al*_(6.364)reaction was carried out by using a 31.5 MeV ~7Li beam from the HI-13tandem accelerator,Beijing.The 200 enA 7Li beam impinged on ~(25)MgO,~(24)MgO and ~(12)C target,     

~7Be(d,~3He)~6Li and Its Effect on Primordial Lithium Abundance

<正>The ~6Li,~7Li abundance can be computed by the[standard Big Bang nucleosynthesis model[1].Surprisingly,the primordial ~7Li abundances of astronomical observations are only about 1/3of the model calculation,while the primordial ~6Li abundances observed by astronomical observa-     

Natural orbital description of the halo nucleus ~6He

Ab initio calculations of nuclei face the challenge of simultaneously describing the strong short-range internucleon correlations and the long-range properties of weakly bound halo nucleons. Natural orbitals, which diagonalize the one-body density matrix, provide a basis which is better matched to the physical structure of the many-body wave function. We demonstrate that the use of natural orbitals significantly improves convergence for ab initio no-core configuration interaction calculations of the neutron halo nucleus ~6He, relative to the traditional oscillator basis.     

3He半导体夹心中子能谱仪

介绍了3He半导体夹心谱仪的探头组件和电子学系统,开展了热中子调试,获得快中子临界装置上0.1-1.3 MeV的能谱数据.测量结果与6Li夹心谱仪在0.3-1.3 MeV范围非常符合,证明该谱仪用于测量快中子临界装置泄漏谱是可行的.     

Detector Calibration for Laser-driven ~2H(d,p)~3 H Nuclear Reaction

<正>The~2 H(d,p)~3H fusion reaction plays a key role in the design of future fusion power plants and in the understanding of the original abundance in the big bang nuclear synthesis (BBN)model.Therefore,in the past few decades,the reaction has been studied using traditional accelerators.Of particular interest is the study of this kind of reaction generated by high-intensity lasers in a plasma environment,which is close to the actual celestial conditions.Recently,     

回旋加速器质谱技术中氚和氦—3粒子的探测和鉴别

在利用回旋加速器质谱技术进行氚断代的测量中,工作气体是电解水样品时收集到的含氚氢气,并混入少许一定量的空气。空气中的微量~3He和样品中的~3H同时加速并被用作参考标准以监督加速器的束流变化。描述了利用金硅面垒探测器望远镜和铝吸收箔的组合来探测和鉴别~3H和~3He的实验方法和结果。     

Energy Dependence of Optical Potentials of Halo System ~6He+~(64)Zn

<正>The angular distributions of the transfer reactions of ~(63)Cu(~7Li,~6 He)~(64)Zn were measured at energies around the Coulomb barrier,to extract and study the optical model potential(OMP)of halo system ~6 He+~(64)Zn in the exit channel.Due to the limit of the intensity and quality of the radioactive ion beam(RIB),it is a difficult task to extract the OMPs of halo nuclear     

中国散裂中子源3He管电子学读出系统研制

介绍了中国散裂中子源(CSNS)高通量粉末衍射仪中3He管电子学读出系统的设计,重点介绍了其中电荷测量插件(MQ插件)的设计,包括了电路结构、FPGA逻辑及其算法的实现.最后给出了与探测器联调的测试结果.