中能重离子核反应的碎裂、集体流和其同位旋效应

本文总结了中能重离子核反应的一般特征及热核反应与衰变过程的动力学、热力学和化学（同位旋组分）效应。尤其是，综合了作者在当前中能重离子核物理研究热点，如多重碎裂，“颈”发射，集体流及其同位旋物理等这些方面的系统性工作，作了较为完整深入的介绍，最后我们还对当前中能重离子核物理的发展前景作了扼要的介绍。     

中等质量核激发态奇异核结构的研究

在球形非线性相对论平均场(RMF)的理论框架下, 研究了β稳定线附近中等质量(z=20—50)奇A核在激发态下存在的晕或皮结构, 提取了价核子与核芯均方根半径的比值(R_vc), 并结合单中子或质子的分离能(Sn(p)), 讨论了具有晕或皮结构的激发态所呈现出来的带状分布, 说明了壳层结构与离心势垒对激发态晕或皮结构形成的重要影响.     

同位旋标度规律的动力学和统计衰变效应

通过同位旋相关的量子分子动力学模型和统计级联衰变模型, 计算了两个相似的同位旋不同的反应系统的同位旋标度规律, 计算的结果表明对于轻粒子碎片, 同位旋标度系数α随反应时间的增加有所变大, 而对于重的余核产物, α随反应时间的增加有所减小; 轻粒子碎片的α基本上保持不变化, 中等质量和重的余核, α与产物的大小相关, 产物越重α越大. 统计级联衰变可以稍微增加同位旋标度参数α, 但是不改变α对于轻粒子和重产物的变化规律.     

One-Proton Halo Structure in ^23Al

The Glauber theory is used to investigate the reaction cross section of proton-rich nucleus ^23Al. A core plus a proton structure is assumed for ^23Al. HO-type density distribution is used for the core while the density distribution for the valence proton is calculated by solving the eigenvalue problem of Woods-Saxon potential The transparency function in an analytical expression is obtained by adopting multi-Gaussian expansion for the density distribution. Coulomb correction and finite-range interaction are introduced. This modified G1auber model is suitable for halo nuclei. A dominate s-wave is suggested for the last proton in ^23Al from our analysis which is possible in the calculation of relativistic mean-field theory.     

化学非平衡夸克–胶子等离子体中的双轻子产生

研究了正在进行化学平衡的具有有限重子密度的夸克–胶子等离子体系统的演化和双轻子产生.结果发现由于夸克相的寿命随初始夸克化学势的增加而增加,以及其他一些因素,如较高的初始温度、较大的胶子密度和较大的胶子聚变和夸克湮没反应截面,导致热粲夸克对双轻子产生提供了占统治的贡献.这个效应造成中等质量双轻子的重大增强.     

Shanghai laser electron gamma source and its applications

Shanghai Laser Electron Gamma Source, a high intensity beam line of γ-ray, is expected to generate γ-rays up to the maximum energy of 22 MeV by Compton backscattering between a CO₂ laser and electrons in the 3.5 GeV storage ring of the Shanghai Synchrotron Radiation Facility. The luminosity of SLEGS γ-ray beam is estimated to be 7×10⁷ A^－1W^－1s^－1 in a optimized setup. Indirect measurement of cross section of the key nuclear-astrophysics reaction ¹²C(α,γ)¹⁶O and γ-ray-triggered transmutation of long-lived radioactive wastes are discussed based on the estimated SLEGS γ-ray beam properties.     

F同位素的反应总截面测量和17F可能的质子皮结构

应用透射法对中能区F同位素与C靶的反应总截面进行了测量.发现¹⁷F的反应总截面比其邻近同位素的反应总截面稍有增强.用Glauber模型和BUU模型对F同位素进行了差异因子d的分析.¹⁷F的差异因子d比其附近同位素稍有增强.分析结果表明¹⁷F可能存在质子皮结构.     

A possible experimental observable for the determination of neutron skin thickness

The dependence between neutron skin thickness and neutron abrasion cross section （σnabr） for neutron-rich nuclei is investigated within the framework of the statistical abrasion ablation model. Assuming that the density distributions for proton and neutron are of Fermi-type, and adjusting the diffuseness parameter of neutron density distribution in the droplet model, we find out the good linear correlation between the neutron skin thickness and the abrasion cross section σnabr for neutron-rich nuclei. The uncertainty of neutron skin thickness determined from σnabr is very small. It is suggested that σnabr can be used as a new experimental observable to extract the neutron skin thickness for neutronrich nucleus. The scaling behaviours between neutron skin thickness and σnabr, separately, for isotopes of ^26-35Na, ^44-56Ar, ^48-60Ca, ^67-78Ni are also investigated.     

Temperature dependent fission fragment distribution in the Langevin equation

The temperature dependent width of the fission fragment distributions was simulated in the Langevin equation by taking two-parameter exponential form of the fission fragment mass variance at scission point for each fission event. The result can reproduce experimental data well, and it permits to make reliable estimate for unmeasured product yields near symmetry fission.