THM方法间接研究天体能区~9Be(p,α)~6Li核反应

为测量9Be(p,α)6Li在天体能区的裸核反应截面,使用了基于准自由反应机制的特洛伊木马方法。该方法通过测量一个适当的三体反应截面提取出所要研究的两体反应在极低能区的裸核反应截面和S(E)因子,从而避免了低能核反应中库仑位垒和电子屏蔽造成的困难,而且无需外推。选用三体反     

37 ^9Be（P，α）^6Li核反应截面的间接测量

核反应^9Be（P，α）^6Li在天体能区的裸核反应截面测量对核天体物理中大爆炸核合成及恒星核合成的机制研究具有非常重要的意义。然而，由于低能带电粒子核反应中库仑位垒和电子屏蔽效应的影响，直接测量^9Be（P，α）^6Li在低能区的截面非常困难。为此，本工作使用基于准自由反应机制的特洛伊木马方法对其进行间接研究。     

特洛伊木马方法间接测量9Be（p，α）6Li核反应截面与直接测量结果的比较

核反应9Be（p,α）6Li在天体能区的裸核反应截面测量对核天体物理中大爆炸核合成及其恒星核合成的机制研究具有极其重要的意义。然而,由于低能带电粒子核反应中库仑位垒核电子屏蔽效应的影响,直接测量9Be（p,α）6Li在低能区的截面非常困难。     

Indirect Measurement of Cross Section of ~9Be(p,α)~6Li

The cross section of 9Be(p,α)6Li at low energies is important for nuclear astrophysics. But it is difficult for direct measurement because of the Coulomb barrier and electron screening effect. In order to measure the 9Be(p,α)6Li bare nucleus cross secti…     

Measurement of Be-profiles by the 9Be(p,α)6Li reaction

The use of the ⁹Be(p,α)⁶Li (E_p = 330 keV) reaction as a tool for the profiling of implanted Be is described.Pile-up problems, caused by elastically scattered particles, requires a mylar foil to be introduced in front of the particle detector. This causes severe straggling and thus loss of depth resolution. A deconvolution technique, which is based on an iterative procedure, is described. With it, profiles are reconstructed with a depth resolution of 300 Å.The present technique was used to assess the diffusion of Be implanted into InSb and GaAs during annealing. Pronounced diffusion accompanied by Be loss was found for GaAs (T_ann = 1113 K, T_melt = 1511 K), while hardly any changes in Be profiles for InSb (T_ann = 670 K, T_melt = 798 K) could be detected.     

特洛伊木马方法间接研究^9Be（p，α）^6Li核反应截面的探测器刻度

核反应^9Be（p，α）^6Li在天体能区的裸核反应截面测量对核天体物理中大爆炸核合成及其恒星核合成的机制研究具有非常重要的意义。然而，由于低能带电粒子核反应中库仑位垒和电子屏蔽效应的影响，直接测量。Be（p，α）^6Li在低能区的截面非常困难。     

关于准自由散射~6Li(p,pd)α与~6Li(p,pα)d的扭曲波冲量近似

本工作利用了坂本(Y.Sakamoto)等人提出的~6Li内a与d集团的相对运动波函数,用扭曲波冲量近似的方法计算得到较好的结果。     

关于准自由散射~6Li(p,pd)α与~6Li(d,dd)α的平面波冲量近似

本文叙述了准自由散射的条件和准自由散射的微分截面公式。用平面波冲量近似分析了100与156兆电子优质子对~6Li准自由散射,以及11与8兆电子伏氘对~6Li的准自由散射。利用坂本(Y.Sakamoto)的~6Li内a集团与d集团的相对波函数,以及改进了的唐(Y.C.Tang)形式的相对波函数均可获得较满意的结果。     

Indirect Measurement of Astrophysical S(E) Factor for ~9Be(p,α)~6Li Reaction by Means of the Trojan Horse Method

The beryllium abundance acts as a key role for understanding the inhomogeneous Big Bang nucleosynthesis. In order to measure the 9Be(p, α)6Li bare nucleus cross section and S(E) factor at astrophysical energies, the Trojan Horse Method (THM) can be appli…     

~8Li(d,p)~9Li天体物理反应率的研究

大爆炸原初核合成的标准模型假定重子密度均匀分布,已经成功预测了直到7Li的原初核合成,并预言仅能合成极少量的重核素,主要是由于没有A=8的稳定核。在重子密度不均匀的非标准原初核合成模型中,该稳定核空隙可通过包含有不稳定核的反应跨越过去,使核合成的反应流延伸到更重的核     

Astrophysical S-factor for ~8B(p, γ)~9C via a Study of the ~8Li(d, p)~9Li Reaction

The 8B(p, γ)9C reaction plays a key role in the 7Be(p, γ)8B(p, γ)9C(α, p)12N chain which is believed to be a breakout path into the hot CNO cycles. 8B(p, γ)9C might be of importance for the evolution of massive stars with very low metallicities where     

Determination of Astrophysical Reaction Rate of ~8Li(d,p)~9Li

The standard baryon homogeneous big-bang model(SBBN) has successfully predicted the primordial nucleosynthesis of elements up to 7Li and synthesized very tiny quantities of the heavier nuclides, primarily because no stable nuclei exist at mass number A= 8…     

THE SUMMARY OF EVALUATIONS OF ~1H,~4He,~6Li,~7Li,~9Be,~(14)N,~(16)O AND MO FOR CENDL-2

The evaluations of neutron nuclear data of ~1H,~4He,~6Li,~7Li,~9Be,~(14)N~(16)O and Mo were completed by various evaluators for CENDL-1 before 1985.Due to the conditions at that time,these evaluated data sets are not complete     

Determination of the Astrophysically Relevant ~6Li(n,γ)~7Li Cross Sections from the ~7Li(~6Li,~7Li)~6Li Elastic-Transfer Reaction

Angular distributions for the ~7(Li)(~6(Li),~7(Li))~6(Li) Li elastic-transfer reaction have been measured with the Q3D magnetic spectrograph at the HI-13 tandem accelerator of Beijing, China. The neutron spectroscopic factors of 7Li are derived by comparing the calculated differential cross sections, which are obtained through the distorted-wave Born approximation (DWBA) calculation, to the experimental data. And these spectroscopic factors are then used to deduce the direct capture cross sections in 6Li(n,γ)7 Li at energies of astrophysical relevance.     

~7Li(α,t)~8Be反应中α集团转移机制的研究

一、引言实验表明~7Li(α,t)~8Be反应角分布(E_α=28.2 MeV,E_α=30 MeV),在后角区有尖锐上升现象。用一般单核子转移DWBA计算,只能解释前角区,而不能拟合后角区。F.Merchez等用PWBAE理论拟合了后角区上升;在计算中他们考虑了四种反应机制,但略去了扭曲效应和取了切断近似。用包括重离子削裂(或拾取)的DWBA计算可能     

Indirect Measurement of Cross Section of ^9Be（p,α）^6Li

The cross section of ^9Be（p,α）^6Li at low energies is important for nuclear astrophysics. But it is difficult for direct measurement because of the Coulomb barrier and electron screening effect. In order to measure the 9Be（p,α）6Li bare nucleus cross section at astrophysical energies, the Trojan Horse Method（THM） can be applied. The main feature of the method is that it allows to extract the energy dependence for the bare astrophysical S（E） factor at very low energies without any extrapolation, by measuring the cross section of an appropriate three body process.     

~(14)N(~7Li,~6He)~(15)O和~(14)N(~7Li,~6Li)~(15)N反应的测量

正H是宇宙中丰度最高的元素,H燃烧反应是恒星重要的能量来源。H燃烧有p-p链和CNO循环两种方式。而~(14)N(p,γ)~(15)O是CNO1循环中最慢的核过程,它控制着整个CNO循环的进程,从而影响对球状星团年龄的判断。球状星团年龄与由哈勃常数确定的宇宙年龄之间的矛盾尚待解决。     

~6Li、~7Li、~9Be、~(12)C和~(16)O及相关奇特核普适光学模型势

<正>光学模型是原子核反应理论最基本和最重要的理论模型之一,光学模型势的研究是其关键。而光学模型势分为微观光学模型势和唯象光学模型势。在非相对论理论的基础上,仔细分析了国际上已有的~6Li、~7Li、~9Be、~(12)C和~(16)O核与不同靶核反应的反应截面和弹性散射角分布的实验测量结果,入射核能量在200 MeV以下,靶核质量数A     

The Astrophysical ~8Li(n,γ)~9Li Reaction Rate

The 8Li(n, γ)9Li reaction has attracted much attention in the recent years because of its importance in astrophysics. Nucleosynthesis of light nuclides is impeded by the gap at mass number A=8, where no stable nuclei exist. In the explosive neutron-rich …     

利用离子注入~(15)N靶研究超低能区~(15)N(p,α)~(12)C核反应

描述了利用离子注入固体靶测量15N(p ,α) 12 C核反应微分截面的实验过程和方法 ,给出了在163keV≤Ec≤ 360keV能区 90°方向上的微分截面测量结果和激发函数曲线 ,并对该反应的基本特征进行了分析和描述。