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     

~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-     

~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-     

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.     

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     

用屏栅电离室测量~6Li(n,t)~4He反应微分截面

用屏栅电离室对 3.6 7MeV与 4 .4 2MeV中子6Li(n ,t) 4He反应微分截面进行了测量。利用氘气体靶通过D(d ,n) 3 He反应产生中子 ,用BF3 和液闪探测器 (NE2 13)进行相对中子通量监测 ,绝对中子通量用2 3 8U(n ,f)与H(n ,p)反应来刻度。测量结果表明 ,氚的质心系微分截面在中子能量为 3.6 7MeV时很接近 90°对称 ,而到 4 .4 2MeV时则明显前倾     

6Li(n,t)4He反应微分截面的实验测量

用屏栅电离室对1．85和2．67MeV中子^6Li(n,t)^4He反应的微分截面及截面进行了测量。使用氚固体靶通过T(p,n)^3He反应产生中子,利用BF3长中子管进行相对中子通量监测,绝对中子通量则用^238U(n,f)反应来刻度。测量结果与已有数据进行了比较。     

Global Phenomenological Optical Model Potential for ~6Li,~7Li,~9Be,~(12)C and ~(16)O as Well as Exotic Nuclei Projectiles

<正>The optical model is one of the most fundamental theoretical models in nuclear reaction theory.The key point of the optical model is how to give the optical model potential.The global phenomenological optical model potential for~6 Li,~7 Li,~9 Be,~(12) C and~(16) O projectiles are studied by simultaneously fitting theexperimental data of the reaction cross sections and elastic scattering angular distributions in the mass range of the target nuclei 20≤A≤209at incident projectile energy below 200 MeV,     

Investigation of the reactions Li6(t,n), Li7(t,n), Li7(He3, n), Be9(t,n)B11, and Be9(He3, n)C11

Neutron yields have been measured in the bombardment of thin targets containing Li⁶, Li⁷, and Be⁹, by tritium and He³ ions, the energies of the accelerated particles ranging as high as 1.4 Mev. The neutron yield from the reactions Li⁶(t, n) and Be⁹(t, n) is proportional to the penetrability of the Coulomb barrier. In the reactions Li⁷(t, n) and Li⁷(He³, n), when the kinetic energies of the accelerated particles are small resonances are detected, corresponding to levels of the component nuclei near the threshold of these reactions. The thresholds for formation of slow neutrons have been investigated in the interaction of tritons with Li⁶, Li⁷, and Be⁹ nuclei. In the reactions Li⁶(t, n)Be⁸ and Li⁷(t, n)Be⁹ slow neutrons are detected, corresponding to the formation of the Be⁸ nucleus in excited states with energies of 16.08, 16.66, and 16.94 Mev and the Be⁹ nucleus in a state with energy 10.50 Mev. In the reaction Be⁹(t, n)B¹¹ no slow neutron thresholds were observed.The nuclear photoemulsion method was used to measure the neutron spectra in all of the investigated reactions at zero angle of incidence. The neutron spectra are in agreement with the established data [1] on the energy levels of the Be⁸, Be⁹, Be⁹, B¹¹, and C¹¹ nuclei.The authors are grateful to all these comrades for their contribution.     

~6Li ~(208)Pb Fusion Around the Barrier

Theinfluenceofthelargebreakupprobabilityofhaloorweaklyboundnucleionfusionhasbeendiscussedextensivelyintheliteratures.However,thequestionofwhetherfusionisenhancedorreducedhasnotyetbeenansweredexperimentally.6Liisaweeklyboundnucleuswithdeuteronseparationene…     

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     

用固体径迹探测器测量~6Li/~7Li比

慢中子与锂引起的~6Li(n,t)~4He和~6Li(n,a)T两种反应产生的α粒子,被聚碳酸酯所记录,通过相对测定锂中~6Li的含量,可得到样品中的~6Li/~7Li比。对测显方法进行了验证,结果与化学法符合较好。     

Elastic Scattering Angular Distributions of ~(16)O from ~(94)Zr,~(116)Sn,~(124)Sn and ~(114)Sm

Elasticscatteringthresholdanomalyandfusioncrosssectionenhancementareimportantphenomenainlowenergyheavyionreactions.Someresearchesindicatethattheyarecorrelativeandhavethesameorigin.Thecoupled-channeltheoryexplainssomeoftheabnormalphenomenasussessfully.Inor…     

Neutron yield of the reactions Li6(t,n) and Li7(t,n)

The differential cross section is determined for the formation of neutrons at an angle of 0 ° in the reactions Li⁶(t,n) and Li⁷(t, n) in the 0.175–2.4 Mev triton energy range. In the reaction Li⁶(t,n) resonance in the neutron yield is observed at E_t = 1.875 Mev, corresponding to a Be⁹ excitation level of 18.936 Mev.Two resonances are detected in the neutron yield of the reaction Li⁷(t, n): at E_t = 0.765 Mev and E_t = 1.735 Mev, which indicates the presence of Be¹⁰ nucleus excitation levels of 17.78 and 18.46 Mev, respectively. The cross section of the reaction Li⁶(t, n) in resonance is d/d(0 °)_res = 37.2 mb/sr; for the reaction Li⁷ (t, n) the cross section at the first resonance is d/d(0 °)_res = 95 mb/sr; at the second resonance d/d(0 °)_res = 159 mb/sr.The angular distributions of neutrons are given for the interval of angles 0–135 ° (every 15 °) for triton energies of 0.358, 0.559, 1.006, 1.218, 1.370, 1.572, 2.123 Mev.The total cross section for the formation of neutrons at E_t = 2.123 Mev in the reaction Li⁶ (t,n) is equal to 324±32.3 mb in the reaction Li⁷ (t, n) to 1332±83.3 mb.     

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     

Study of Optical Potential of Weakly Bound System ~7Li+~(63)Cu

正The angular distributions of the elastic scattering of weakly bound nuclear systems of~7Li+~(63)Cu were measured at energy around the Coulomb barrier,to extract and study the optical model potential(OMP)of this weakly bound system.For the weakly-bound nucleus ~7Li,there are large amount of elastic scattering data.However,     

Measurementof the Fusion Excitation Function for the System ~6Li ~(208)Pb

Theinfluenceofthebreakupofhalonucleionsub-barrierfusionhasattractedrecentlymuchinterest.Manytheoreticalworkshavebeendoneonthistopicwithconflictingresultssincebothenhancedandhinderedfusioncrosssectionsarepredicted.Therefore,itisneces-sarytotestthevariousth…     

~(125)I,~(139)Ce等七种核素溶液的比活度测量

简述了125I,139Ce,88Y,57Co,60Co,137Cs和134Cs放射性核素的衰变特性及采用符合法、4πγ电离室法、γ谱仪法、合峰法测量其比活度的测量原理。给出了比活度测量结果,并与中国计量科学研究院的测量结果进行了比较,两者在不确定度范围内有较好的一致性。     

Long-rallge angular correlation in dissipative reaction of ~(27)Al ~(27)Al

1 INTRODUCTIONOne of the most boortat results on the study of heavy ion physics is discovery ofthe so-called deep inelastic collision (DIC). The interpretation of the DIC is based on apicture of the formation and decay of an intermediate dinuclear system (IDS). Withinthe lifetime of IDS, the relative kinetic energy is transformed into the intrinsic excitationenergy of the system and the orbital momentum into intrinsic angulax momentum ofthe system. The transformation is a dissipative…