反馈抑制HLS注入过程中β振荡的尝试

为了提高注入束流的积累,抑制由于注入系统误差所引起较大的β残余振荡是非常有必要的.本文较系统地介绍了合肥光源(HLS)抑制注入β振荡反馈系统的设计思想、原理和线路,并提供了它的初步实验结果.作为原理论证和预研,我们使用了一个相对简单的模拟滤波器和移相器对Kicker过程激发的β振荡进行反馈,看到了明显的抑制作用.为以后研制低频和高频反馈系统,研究抑制束流的横向和纵向不稳定性打下基础.     

B→π跃迁形状因子中扭度为3的分布振幅

我们选择了恰当的手征流关联函数,用光锥QCD求和规则去计算B到π的跃迁形状因子,得到的结果仅仅依赖于π介子的3扭度光锥分布振幅.这样从f+?Bπ的研究中,我们就可以对π介子的3扭度光锥分布振幅给出一个约束条件.     

强化对流传热场协同唯象机制及其控制

根据对流传热强度与流体中存在的各种内场及其外场的关系,从唯象上阐明了降低温度边界层厚度、增加流体扰动和增加近壁面速度梯度的强化对流传热方法的物理机制,其本质是控制流体中内场及其外场之间的相互协同。给出了当流体中存在内场和外场时强化对流传热场协同控制方法,以此可指导发展强化对流传热单元的新方法。     

静电场强化介电流体冷凝换热实验研究

本文以电绝缘性低沸点介电流体R11为实验工质,利用自行设计和制作的电流体力学实验模型,对介电流体进 行静电场强化冷凝换热实验研究。实验结果表明:静电场对模型内介电流体的凝结换热有很好的强化作用,其换热系数主 要与外加电场强度、热通量及电极相对位置等因素有关,这种电场强化凝结换热技术对制冷和热传递工程具有参考价值。     

合肥光源二分割三角型光位置检测器的研制

介绍了一种用于合肥光源的二分割三角型光位置检测器的研制,对其主要性能(如灵敏度和线性范围)进行了理论分析和实际测量,测量结果与理论分析相当吻合.文中还给出了光位置测量系统的组成     

三线摆法测刚体的转动惯量所用近似方法对测量结果的影响

讨论了在推导转动惯量的测量公式时采用的近似方法对测量结果带来的影响,指出了减小其影响的途径.     

多媒体在二维动量实验中的应用

利用VisualBasic的多媒体功能和CCD摄像头以及气垫桌等组成的实验系统，演示了二维碰撞中的动量守恒．     

X波段长脉冲同轴多注相对论速调管放大器的分析与设计

为了提高相对论速调管放大器的工作频率、输出功率以及转换效率, 结合三重轴相对论速调管和多注速调管的特点, 采用三维电磁粒子模拟软件分析与设计了工作在X波段的长脉冲同轴多注相对论速调管放大器, 通过优化设计有效地抑制了X波段长脉冲相对论速调管放大器的自激振荡, 避免了脉冲缩短现象的产生, 使X波段相对论速调管放大器在长脉冲状态下能够稳定工作, 在注入微波功率为70 kW、束压为600 kV、束流为5 kA、轴向引导磁感应强度为0.8 T的条件下, 输出微波功率达到了1.23 GW, 效率为41%, 增益为42 dB.     

The interplay between the lattice and magnetism in La（Fe11.4Al1.6）C0.02 studied by powder neutron diffraction

The crystallographic structure and magnetic properties of La（Fell.4Alz.6）C0.02 are studied by magnetic measurernent and powder neutron diffraction with temperature and applied magnetic field. Rietveld refinement shows that La（Fe11.4Al1.6）C0.02 crystallizes into the cubic NaZn13-type with two different Fe sites： FeI （8b） and FeII （96i）, and that A1 atoms preferentially occupy the FeII site. A ferromagnetic state can he induced at a medial temperature of 39 K-139 K by an external magnetic field of 0.7 T, and a large lattice is correspondingly found at 100 K and 0.7 T. In all other conditions, La（Fe11.4Al1.6）C0.02 has no net magnetization in the paramagnetic （T 〉 TN = 182 K） or antifer- romagnetic states, and thus keeps its small lattice. Analysis of the Fe Fe bond length indicates that the ferromagnetic state prefers longer Fe-Fe distances.     

Radiation characteristics and implosion dynamics of tungsten wire array Z-pinches on the YANG accelerator

We investigated the radiation characteristics and implosion dynamics of low-wire-number cylindrical tungsten wire array Z-pinches on the YANG accelerator with a peak current 0.8-1.1 MA and a rising time ～ 90 ns.The arrays are made up of(8-32)×5 μm wires 6/10 mm in diameter and 15 mm in height.The highest X-ray power obtained in the experiments was about 0.37 TW with the total radiation energy ～ 13 kJ and the energy conversion efficiency ～ 9%(24×5 μm wires,6 mm in diameter).Most of the X-ray emissions from tungsten Z-pinch plasmas were distributed in the spectral band of 100-600 eV,peaked at 250 and 375 eV.The dominant wavelengths of the wire ablation and the magneto-Rayleigh-Taylor instability were found and analyzed through measuring the time-gated self-emission and laser interferometric images.Through analyzing the implosion trajectories obtained by an optical streak camera,the run-in velocities of the Z-pinch plasmas at the end of the implosion phase were determined to be about(1.3-2.1)×10 7 cm/s.