Production Of ～(10)C Secondary Beam And Astrophysical Reaction Rates Of The ～8Li(p,γ)～9Be_g.s. Direct Capture Reaction.

In the evolution of the universe, nuclear process plays a pivotal role for both energy production and nucleosythesis. Nuclear astrophysics, which combines astrophysics and nuclear physics, has been developed in the twentieth century. Lots of nuclear reactions induced by unstable nuclei are very important in nuclear astrophysics. These reactions can not be investigated by traditionary stable beam nuclear experiments, while a new technology, radioactive nuclear beam(RNB) makes it possible.The standard big-bang model(SM), which assumes a homogeneous isotropic early universe, has proven to be very successful for predicting the primordial abundances of the light elements up to ⁷Li, but it does not produce significant yields beyond A =7 because of the particle instability gap at A—8. However, the inhomogeneous models(IMs) allow a higher production of A > 7 nuclides because the IMs assume a universe with regions of high-density proton-rich material surrounded by those of low-density neutron-rich one. In these inhomogeneous environments, unstable isotopes can be generated to open up more reaction pathways to the heavier nuclides. Among them, the ⁸Li(α,n)¹¹B reaction plays a crucial role in bridging the A = 8 gap. Since the synthesis of the heavier nuclides via ⁸Li scales with the ⁸Li abundance during primordial nucleosynthesis, all the reactions which create or destroy ⁸Li are important in the IMs . The ⁸Li(p,γ)⁹Be_g.s. reaction is of importance because it not only destroys ⁸Li but also leads to the production of ⁹Be, which serves as a precursor to heavier nuclides. Moreover, ⁸Li(p,γ)⁹Be_g.s. is involved in the extend reaction network for the r-process nucleosynthesis of type II supernove.In present work, the single particle spectroscopic factor for the ground state of ⁹Be=⁸Li(?)p was extracted from the ⁸Li(d,n)⁹Be_g.s. angular distribution, based on distorted wave Born approximation (DWBA) analysis. We then deduced the astrophysical S-factors and reaction rates of the ⁸Li(p,γ)⁹Be_g.s. direct capture reaction at energies of astrophysical interest. Some reactions induced by unstable nucleus ¹⁰C are involved in the reaction network of the primordial nucleosynthesis. For investigating these reactions , a ¹⁰C beam is produced via the ¹⁰B(p, n)¹⁰C reaction in inverse kinematics on the secondary beam line of the HI-13 tandem accelerator at China Institute of Atomic Energy. The purity of the collimated ¹⁰C beam is better than 90% after the magnetic and velocity selection. The beam energy is (55.9±0.9) MeV and the intensity is about 6 s^-1·pnA^-1.