81Rb高自旋超形变的实验证据

利用⁵⁵Mn(³⁰Si,2p2n)反应布居了⁸¹Rb的高自旋态,GASP阵列配以由40个ΔE-ESi(Au)望远镜单元所组成的4π带电粒子球进行γγγ带电粒子(质子和α)的符合测量;实验发现了由7条级联γ跃迁所组成的⁸¹Rb高自旋超形变转动带. 其动力学惯量为J⁽²⁾=4/ΔEγ=26.7(h²/MeV),该带被解释为具有四极形变参数β₂=0.51以及高N侵入组态为π5¹v5².     

Measurement of PV asymmetry in n＋p→d＋γ and γ＋d→n＋p

The measurement of parity-violating （PV） observables in few-nucleon system can shed light on our current understanding of the weak interaction between nucleons.Theoretical models describe the nucleonnucleon weak interaction at low energies use a series of undetermined parameters.Two parity violating measurements have been considered： the capture of polarized slow neutrons on hydrogen （n ＋ p → d ＋ γ） at Los Alamos National Laboratory for first phase and Oka Ridge National Laboratory for second phase and the helicity dependence of the deuteron photodisintegration cross section using circularly polarized photons （γ ＋ d → n ＋ p） at Shanghai Institute of Applied Physics.The goal of both experiments is to constraint the weak meson-nucleon couplings to a precision of 1 ×10^-8 .The introduction of both experiments is presented.     

用光学极限的Glauber模型结合相对论平均场对8Li和8B的半径的研究

We study the reaction cross sections （σR） and root-mean-square （RMS） radii of ^8Li and ^8B, the halo-like nuclei, with stable target ^12C, ^27Al and ^9Be within the standard optical-limit Glauber model, using densities obtained from relativistic mean-field （RMF） formalisms and other types of distributions. It is found that the experimental σR can be reproduced well at high energy. The RMS radius and Ar extracted by RMF- theory and harmonic oscillator distribution are compared. larger than those of SLi. In addition, we analyze in detail the We find that the RMS radius and Ar of SB are relationship between σR and density distribution.     

146Tb的能级结构研究

利用能量为161—175MeV的³²S束流,通过反应¹¹⁸Sn(³²S,1p3n)¹⁴⁶Tb研究了双奇核¹⁴⁶Tb的高自旋态能级结构. 实验进行了γ射线的激发函数、γ射线的各向异性度、X–γ和γ–γ–t符合测量. 基于这些测量结果,建立了激发能达8390kev的¹⁴⁶Tb核的能级纲图,其中包括新发现的41条γ射线和新建立的27个能级,并指定了¹⁴⁶Tb新发现能级的自旋值. 用一个h_11/2价质子和一个h_11/2^－1价中子空穴耦合、πh_11/2υh_11/2^－1与¹⁴⁶Gd核实激发态的耦合对¹⁴⁶Tb的能级结构进行了定性地讨论.     

实验测定183Os的QEC值

用39MeV-α粒子轰击天然钨靶产生了¹⁸³Os测量了¹⁸³Os衰变的γ-β符合谱,确定了β⁺能谱的端点能量.最终提取出 衰变的QQ_EC值:Q_EC=2.24±0.10MeV,与系统学的估计值;2.30±0.10MeV在误差范围内相符.     

新丰中子同位素:186Hf

在兰州重离子加速器(FDUL)上,用60MeV/μ ¹⁸O离子轰击厚天然钨靶,通过多核子转移反应产生¹⁸⁶Hf. 使用放射化学分离技术从钨和反应产物混和物中分离出铪,并由HPGe探测器测量铪样品的活性.观测到了¹⁸⁶Hf的子体¹⁸⁶Ta的737,5keVY射线的增长、衰变行为,结果表明,本实验首次合成并鉴别了新丰中子同位素¹⁸⁶Hf,测得它的半衰期为(2.6±1.2)min.     

EC/β+ decay of six medium-heavy nuclei

Previous experimental results of (EC+β+) decay for the medium-heavy nuclei reported by our group since 1996, including 153Er, 157Yb, 209Fr, 128Ce, 130Ce, and 128Pr have been briefly summarized. The observed low-lying states in their daughter nuclei have been reviewed in a systematic way and compared with different model calculations. Finally, some questions have been put forward for further study and discussion.     

EC/β+ decay of six medium-heavy nuclei

Previous experimental results of (EC+β⁺) decay for the medium-heavy nuclei reported by our group since 1996, including ¹⁵³Er, ¹⁵⁷Yb, ²⁰⁹Fr, ¹²⁸Ce, ¹³⁰Ce, and ¹²⁸Pr have been briefly summarized. The observed low-lying states in their daughter nuclei have been reviewed in a systematic way and compared with different model calculations. Finally, some questions have been put forward for further study and discussion.     

Transmutation of nuclear wastes using photonuclear reactions triggered by Compton backscattering photons at the Shanghai laser electron gamma source

Based on the facility of the Shanghai Laser Electron Gamma Source (SLEGS), the transmutation for nuclear wastes such as ¹³⁷Cs and ¹²⁹I is investigated. It is found that nuclear waste can be transmuted efficiently via photonuclear reaction triggered by gamma photons generated from Compton backscattering between CO₂ laser photons and 3.5 GeV electrons. The nuclear activities of ¹³⁷Cs and ¹²⁹I are evaluated and compared with the results of transmutation triggered by bremsstrahlung gamma photons driven by ultra intense laser. Due to the better character of gamma photon spectrum as well as the high brightness of gamma photons, the transmutation rate of Compton backscattering method is much higher than that of the bremsstrahlung method.     

Measurement of electric polarizabilities of light nucleus(nucleons)

The measurement of the electromagnetic polarizabilities have been given extensive attention, which is also a fresh field of the experimental nuclear physics. Now we will use the method - the light nucleus scattered by the heavy nucleus at energies below the Coulomb barrier to precisely and systematically measure the polarizabilities of the light nucleus. We hope we can solve the inconsistency among the results of the ³He polarizabilities and extract the ⁴He polarizabilities by our experiment. It is useful to mention that our experiment now is a supplement to the future experiment on SLEGS.