Determination of Astrophysical ^26Si（p, γ）^27p Reaction Rate From Asymptotic Normalization Coefficients of ^27Mg →^26Mg ＋ n

The 1.809 MeV T-ray from the decay of ^26Al is an excellent observable for some astrophysical events, such as novae and X-ray burst. The nucleosynthesis of ^26A1 is dominated by the reaction chain ^24Mg（p,γ）^25Al（β＋）^25Mg（p,γ）^26Al, however,     

~(25)Mg(p,γ)~(26)Al Astrophysical Reaction Rate

<正>A total ~(26)Al mass were derived through the analysis of the measured gamma spectra by the COMPTEL telescope.The ~(25)Mg(p,γ)~(26)Al reaction is the main way to produce ~(26)Al in the galaxy and its astrophysical reaction rates are dominated by the capture reactions of isolated narrow resonances in the ~(26)Al excited state.Up to date,the     

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 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 …     

Astrophysical ~(13)N(p,γ)~(14)O Reaction Rate

13N(p,γ)14O is is one of the key reactions in the hot CNO cycle which occurs at stellar temperatures around T9≤0.1. At the energies of astrophysical interest, the 13N(p,γ) 14O reaction is dominated by the     

Astrophysical 13N（p, γ）14O Reaction Rate

13N（p, γ）14O is is one of the key reactions in the hot CNO cycle which occurs at stellar temperatures around T9≤0.1. At the energies of astrophysical interest, the 13N（p, γ）14O reaction is dominated by the low energy tail of the s-wave capture on the broad 1- resonance at Er = 527.9 keV （which has a total width of （37.34-0.9） keV）. A considerable effort has been expended in recent years to determine the parameters for the resonance. These include the direct measurements using the radioactive ^13N beam, particle transfer reactions, and coulomb dissociation of high-energy ^14O beams in the field of a heavy nucleus.     

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

由于放射性核素的半衰期特别是发生电子俘获和内转换过程的半衰期与核外电子密度有关，因而改变核外物理、化学环境就有可能改变核素的半衰期。精确测量这些核素的半衰期以及研究它们在不同核外环境中半衰期的变化在许多领域有着重要的应用。^7Be是发生电子俘获最轻的放射性核素，具有简单的电子壳层结构，并且^7Be电子俘获会伴随放出478keVγ射线，因此常被人们用来研究核的衰变率变化。     

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     

Indirect Measurement of 58 keV Resonance of ~(25)Mg(p,γ)~(26)Al via(~7Li,~6He)Reaction

正~(25)Mg(p,γ)~(26)Al is one of the key reactions for Mg-Al cycle in explosive hydrogen burning of stars.Its cross sections at star energies are essential to understand the problem of ~(26)Al and ~(26)Mg abundances.It is very difficult to direct measure the 58 keV resonance in ~(25)Mg(p,γ)~(26)Al reaction.Because of the interference of the     

Measurement of Cross Sections for the Reaction ~(27)Al(n,p),~(56)Fe(n,p)and ~(64)Zn(n,2n)of 14.6MeV Neutrons and Simultaneous Evaluation of Some Cross Sections

1.Measurements The experiments were performed on 400 kV Cockcroft-Walton acceleratorof Nanjing University,using the T(d,n)~4He reaction to produce 14.6MeVneutrons.The energy of the incident deuterons was 200keV,the deuteroncurrent was 40μA,and the neutron yield was about 2×10~8 n/s.The ZnS neu-tron detector was used as flux monitor.Each sample to be measured was packedtogether in two standard sample foils of the same dimensions(2×1cm~2 rectang-lar foils and purities better than 99.5%)to form a sandwich so that they areirradiated in the same geometry.The γ-ray activities of the irradiated samplesand monitor foils were measured with a GEM-25210 type HPGe γ-spectrometer.The efficiency of this detector was determined with a ~(152)Eu standard γ source.     

利用ANC方法间接确定天体物理反应~(26)Si(p,γ)~(27)P的反应率

26Al衰变放出能量为1.809MeV的γ射线,该射线在诸如新星、X射线爆炸等天体物理事件中是一个极好的观测量。26Al主要通过反应链24Mg(p,γ)25Al(β )25Mg(p,γ)26Al合成,然而26Al的合成由于其短寿命(T1/2=6.34s)同质异能态的存在而变得复杂。26Si(p,γ)27P能跨越26Al的主要产生链     

Indirect Measurement of 57.7 keV Resonance Strength for ~(25)Mg(p,γ)~(26)AI via(~7Li,~6He) Reaction

<正>~(25)Mg (p,γ)~(26)Al is the most important reaction in the Mg-Al cycle in the hydrogen burning regions of stars.Its cross sections at stellar ener-gies are essential to understand the issues of radioactive~(26)Al in the Galaxy and meteorites.The57.7 keV is one of the dominant resonances forthe~(25)Mg (p,γ)~(26)Al astrophysical reaction rates,     

Measurement and Calculation of Recoil Ranges of 27Mg and 24Na in the Reactions 27Al(n,p) 27Mg and 27Al(n, α)24Na

Since aluminum is widely used in reactor construction, the recoil ranges of ²⁷Mg and ²⁴Na produced by the (n, p) and (n, α) reactions play an important part in evaluating the amount of activity in the coolant of swimming pool type reactors. These recoil ranges however do not seem so far to have been studied in any great detail. Acrylic acid resin vessels containing aluminum sheets immersed in water were irradiated in the H.T.R. (Hitachi Training Reactor), after which the activity from the water was measured by β-γ coincidence. Background activity was determined by preparing blank water samples in which aluminum sheets were soaked for the same time interval without irradiation. Argon-41 activity was corrected by taking the decay curves from each of the coincidence channels. Aluminum foils were also irradiated dry and counted to determine the reaction rate. Recoil ranges of ²⁷Mg and ²⁴Na thus determined were 4.18×10^-5cm and 1.37×10^-4 cm respectively, which agreed well with calculated values.     

Expressions for the ~(18)F(p,α) ~(15)O and ~(18)F(p,γ) ~(19)Ne Astrophysical Reaction Rates

Hydrogen is burned explosively in stellar explosions such as novae, X-ray bursts, X-ray pulsars, and supemovae, as well as possibly in other exotic astrophysical environments such as accretion disks around black holes, Thorne-Zytkow objects, and supermassive stars. Temperatures in these environments range from 107 to 109 K and above, and densities from 102 to 106g/cm3. In such sites,     

Indirect Measurement of Astrophysical ~(13)C(α,n)~(16)O S-Factors

The 13C(α,n)16O reaction is believed to be the main neutron source reaction for the s-process in asymptotic giant branch (AGB) stars. The astrophysical S-factors of this reaction have been determined based on an evaluation of the α spectroscopic factor of the 1/2+ subthreshold state in 17O (Ex=6.356 MeV) by using the 13C(11B,7Li)17O α transfer reaction. Our result confirms that the 1/2+ subthreshold resonance is dominant for the 13C(α,n)16O reaction at low energies of astrophysical interest.     

~(25)Mg(p,γ)~(26)Al天体物理反应率

正~(25)Mg(p,γ)~(26)Al反应是γ射线天文学研究中最为重要的反应。通过它的测量不仅可以研究星际~6 Al的来源,也可以追踪太阳系形成的触发事件。为精细地对~(25)Mg(~7Li,~6He)~(26)Al反应布居6.364 MeV的激发态进行系统的理论分析,同时分析了~(26)Al中所有3~+的激发态,以验证实验提取的光学势和模型计算的一致性。实验在北京串列加速器Q3D磁谱仪上完成,图1为实验得到的~(25)Mg(~7Li,~6 He)~(26)Al反应布居4个3~+态的实验角分布,从中提取的核谱因子也与理论计算符合很好,从而验证了理论计算中使     

The ~(11)C(p, g)~(12)N Reaction Rate and the Conversion of ~3He Into CNO

The reaction sequence of 3He(a, g)7Be(a, g)11C(p, g)12N to CNO could be an alterative way to convert 3He into CNO instead of 34He 12C. It may become important in some specific environments, such as in the very massive stars with low multiplicity. Whether …     

Measurement of ~(17)F(d, n)~(18)Ne Reaction

Explosive hydrogen burning occurs in very massive (M≥105-108 M) star with high temperature and density. Hot pp chain, hot CNO, hot NeNa-MgAl chain and the flowing γp and αp process will play a prominent role in hydrogen burning as the temperature goes …     

Indirect Measurement of ~(59)Fe(n,γ)~(60) Fe Reaction

<正>The long-lived~(60) Fe is a very interesting tracer isotope for the nucleosynthesis in the galaxy and supernovae near the solar system.~(59)Fe (n,γ)~(60)Fe reaction is considered to be the key reaction to produce~(60)Fe in massive stars.To determine the neutron capture cross section experimentally,