(p,n)和(p,2n)反应激发函数的系统学研究

从普朗克(Planck)黑体辐射公式和实验测量数据出发,采用唯象的方法提出了包含两个可调参量,入射质子能量从阈能到150MeV,靶核质量数在44相似文献   

Identification and Analysis of Magnetic Structures on HL-2A

1 Introduction Tearing modes in tokamak plasmas have been studied for many years In HL-2A tokamak, MHD instabilities are investigated by means of the Mirnov probes. The mode number can be determined by the methods of phase comparison analysis or correlation analysis from the experimental data of Mirnov probes, but the analysis of complicated mode structures is difficult. An identification and analysis method of magnetic islands is presented basing on simulation of the perturbation current and magnetic field in plasmas.     

恒星内部核反应区的振荡

用非平衡热力学理论处理受引力和温度梯度影响的热核反应系统的反应扩散方程，考虑３α（３个Ｈｅ＾４合成Ｃ＾１２）反应的粒子数密度的振荡。ｇ－Ｔ可激发超临界的振荡分歧，而压力的影响则使振荡衰减。     

与核能有关的中子数据和核反应研究

介绍开展了中子核反应研究和数据测量的重要性，并扼要介绍了在北京大学重离子物理研究所４．５ＭＶ静电加速器单色中子源开展的中子实验工作。     

58Co核拉长态性质的实验研究

利用△E-E望远镜及北京Q3D磁谱仪系统.在HI-13串列加速器提供的35MeVα离子轰击下,测量了⁵⁶Fe(аd)⁵⁸Co核反应的精细能谱和微分截面角分布.借助全微观DEBA理论分析,相应于核反应俘获的p-n核子对具有(lg_9/2)²组态,观测到迄今所能看到的最高拉长态(lg_9/2,lg_9/2)_9.还对6.4 MeV高激发能级核反应截面的反常增强,而p-n核子对耦合成最小角动量的实验证据进行了讨论,并且确认了6.4MeV能级为非自然宇称态,自旋字称值J^л=1⁺.     

Sigma Meson Production in Nuclear Reactions

The sigma meson production in p ＋ ^12C and p A- ^40Ca reactions at the incident energy Ep = 1.5 GeV is investigated within the Quantum Molecular Dynamics model. The simulation results indicate a distinctive A dependence of the sigma production, that is, the increase of A is followed by an increase of the production cross sections. We find that the σ meson production in proton-induced reactions is strongly medium-dependent, and the produced σ mesons decaying in a denser medium experience a stronger mass shift towards lower masses. This mass shift is an experimentally accessible observable in the final state pion pairs, which do not suffer from reabsorption by the surrounding nucleons. It is pointed out that the ratio of measured sigma cross sections as a function of the sigma invariant-mass from various reactions is a good probe to explore the existence of the σ meson in a dense nuclear environment.     

ECR氧离子源及整体分离环RFQ加速器低能输运系统的研制

根据研制分离作用RFQ和升级改造1MeV ISR RFQ的需要,设计了一台ECR O⁺离子源及低能输运(LEBT)系统. 低能输运系统使用2个静电透镜聚焦束流, 在引出电压22kV时, LEBT末端得到6mA以上总脉冲束流、束流归一化均方根发射度为0.12πmm﹒mrad. 束腰可前后移动160mm.     

用振动密耦合方法研究低能电子与N2分子碰撞的振动激发微分散射截面

采用振动密耦合方法,分别应用球高斯分布极化势和优于绝热极化势,及基于量子力学从头计算的静电、交换势,得到入射电子能量2.40eV时0→2和0→3的振动激发微分散射截面,与目前优秀的实验值比较,获得了满意的结果,并从理论上分析了整个计算过程中可能影响微分散射截面精度的主要物理因素.