基于傅立叶变换的射频场分布测量方法

提出了一种基于傅立叶变换的射频场分布测量方法，该方法可以方便地测量出射频场的分布，其测量结果与样品的均匀度无关并且可以分别观测某个像素点处的层内射频场非均匀性或某个小区域内的射频场非均匀性.     

CRRFA-30L波段射频加速器

 主要介绍CRRFA-30L波段射频加速器结构和性能，论述了热阴极射频腔注入器、束流加速系统、微波功率源和控制等结构中主要技术及其研究进展，给出了加速器输出束流参数测量与测量结果分析，达到设计应用要求。     

CRRFA-30L波段射频加速器

主要介绍CRRFA-30L波段射频加速器结构和性能，论述了热阴极射频腔注入器、束流加速系统、微波功率源和控制等结构中主要技术及其研究进展，给出了加速器输出束流参数测量与测量结果分析，达到设计应用要求。     

射频辉光放电等离子体的电探针诊断

本文简要叙述了探针诊断技术的作用，比较了单、双探针测量技术的异同，分析了当前所碰到的主要问题和各种可能的解决办法。着重报导了我们提出和制作的加热调谐单探针装置，不仅抑制了射频干扰，还克服了中毒效应对探针测量的影响。首次成功地测量了射频辉光放电硅烷等离子体的电子能量分布函数、电子平均能量和密度。并对测量结果进行了简要的分析。     

射频S参数测试技术

S参数是网络分析仪的基本测量参数，它包括了反射系数（驻波系数）、传输系数（或衰减系数）、相位等参数。通过引进射频矢量网络分析仪，可完善和建立本单位射频S参数测试标准，实现S参数量值统一，开展仪器设备和元部件的射频S参数现场及实验室检定。     

波导-同轴线的脊型转换器设计与测试

射频测量系统中经常会用到波导-同轴线转换器，主要是利用其将射频器件的波导端口转换成能够直接接入测量仪器的50 Ω同轴线。本文设计的648 MHz/WR1500波导同轴转换器主要用于CSNS升级工程（CSNS-II）超导直线射频器件的测量。利用切比雪夫脊型阶梯阻抗变换和探针耦合的方式实现波导到同轴线的转换。对脊加载波导和不连续同轴线分别进行了分析，得到最优尺寸。为了提高测量精度，设计的波导-同轴线转换器具有低插入损耗、低驻波比和宽带宽等特性。最后对生产的转换器进行了测试，测试结果与仿真结果相近，能够满足作为测量器件的使用要求。     

兰姆（Lamb，Willis Eugene，1913-）美国物理学家（Physicist，America）

波谱学是通过射频或微波电磁场与物质的共振相互作用研究物质性质和结构的学科。频率范围为10^4-10^12 Hz，测量以频率为主。由于射频和微波的能量子比可见光小得多，因而测量精度高，常用来测定原子的磁矩和电四极矩。分子束是高真空中定向运动的分子流，彼此间相互作用很小，因而可以看作孤立的原子和分子的结合，是研究原子和分子性质的有力工具。     

射频放电阻抗测量用于等离子体诊断研究

利用自行研制的传感器和测量装置,通过对射频放电电压、电流以及其相位角的精确测定,算出放电管的总阻抗,结合放电管的等效电路模型与Godyak等建立的射频放电模型,对射频激励铜离子激光管在氦气中的放电特性进行了研究,得出射频激励铜离子激光器不同气压及电流密度下的等离子体电阻、容抗、鞘层厚度及电子密度 关键词： 射频放电 阻抗测量 等离子体诊断     

L波段射频加速器电子束微脉冲诊断

 利用切伦柯夫辐射的瞬时发光机理，把相对论电子束打在熔石英靶片上转化为可见光，再用皮秒扫描相机进行测量，就可得到射频直线加速器皮秒电子束微脉冲的峰值电流及微脉冲束团。采用该方法，对L波段射频直线加速器的电子束微脉冲宽度和束团结构进行了诊断。由此构建了一套加速器电子束微脉冲的在线测量系统，该系统对调整加速器工作状态、提高束流品质使之适应自由电子激光要求起到了重要作用。     

基于量子相干效应的无芯射频识别标签的空间散射场测量

基于原子蒸汽池中铯里德伯原子的电磁感应透明光谱在微波场作用下的Aulter-Towns效应,测量了无芯射频识别标签线形散射单元的近场散射微波电场二维空间分布,空间分辨率可达到亚微波波长.实现了射频电场极化方向与线形散射体标签夹角的有效分辨.电磁仿真软件的仿真结果与实验测量符合得很好.本研究提供了一种测量微波电场近场测量的新方法,对无芯射频识别标签的散射单元设计和标定以及电子电路的电磁辐射测量具有重要的意义.     

HL—1M装置器壁硅化对电子速率分布的影响

在欧姆加热和低混杂波电流驱动条件下,利用磺化汞半导体探测器和碘化钠和探测器测出了ＨＬ－１Ｍ装置的Ｘ射线能谱,研究了器壁硅化前后电子速率分布和电子温度变化的特点,给出了Ｘ射线辐射强度与ＬＨＣＤ能量沉积的关系。     

Investigations of the mega-ampere multiwire X pinch

The results of experimental investigations into the dynamics of a plasma produced in the multiwire X pinch at currents up to 2.3 MA are presented. The materials, diameters, and the number of wires are varied. At such currents, the power of the soft x-ray radiation with the photon energy from 1 to 2 keV increases to 120 GW, and, since the size of a hot spot is less than 20 μm, it corresponds to a source brightness of ～10¹⁵ W/(cm² sr). The energy recorded in lines of neon-like molybdenum (in the range of 2.5–3 keV) is higher than 10 J. Hard x-ray radiation detected in experiments with tungsten and molybdenum X pinches has the photon energy ≥800 keV.     

Arq+入射金表面激发靶原子Mα-X射线的动能和势能的阈值

在兰州重离子加速器国家实验室 用动能150 keV和1.2 MeV的Ar^q+束流分别入射Au表面, 测量了离子与表面相互作用过程中辐射的X射线谱. 结果表明, 多电荷态Ar^q+激发Au原子的M_α-X射线至少需要2 keV的势能. 本文采用半经典两体碰撞近似, 估算了炮弹离子通过碰撞激发靶原子辐射X射线的动能阈值.     

电子温度对HL－1托卡马克低杂波电流驱动的影响

本文利用较简单的计算模型计算低杂波沿射线轨迹的能量沉积和电流分布。结果表明，当等离子体中心电于温度不太高（Ｔｅ＜１ｋｅＶ）时，边缘冷等离子体区电子－离子碰撞吸收的能量占相当大的比例，因此电流驱动效率较低。提高中心和边缘电子温度，将较大幅度地增加低杂波电流驱动效率，从而可解释为什么在小托卡马克中低杂波电流驱动效率比在大、中型托卡马克中小得多。     

X射线与影像增强器作用过程的蒙特卡罗研究

用蒙特卡罗方法研究了能量为（３０～１１０）ｋｅＶ的单能Ｘ射线在铁中的吸收及散射特性，给出了散射光子的角人布及背向向射光子的能量分布，结果表明，在入射Ｘ光子能量较低的情况下，背向散射光子主要是铁的特征Ｘ射线光子，随着入射能量的升高，背向散射光了中高能量的散射光子数增多，特征Ｘ光子数目迅速减少。     

Excitation of X rays by electrons accelerated in air in the wake wave of a laser pulse

The characteristics of X rays of a laser plasma generated in the interaction of a femtosecond pulse with solid targets in an air atmosphere have been investigated. It has been shown that the mechanism for the generation of X rays in the interaction of short intense laser pulses with solid targets in a gas atmosphere is attributed to the generation of fast electrons in the region of the filamentation of a laser pulse. It has been proven experimentally that under such conditions, the solid target irradiated by laser radiation of even a low density of about 10¹⁵ W/cm² very efficiently emits ∼10-keV photons. It has been shown theoretically that the maximum energy of accelerated electrons can reach ɛ_max ∼ 100–200 keV under these conditions. This means that the proposed method can provide characteristic radiation with the energy of photons much higher than 10 keV.     

Three Dimensional Angular Distributions of X‐Rays in a 4 kJ Plasma Focus Device for Different Anode Tips Using TLD‐100 Dosimeters

Time and energy integrated measurements of the 3‐D angular distribution of X‐rays emission within the chamber of a 4 kJ Mather‐type plasma focus is investigated employing four different anode shapes and using nitrogen as the filling gas by the TLD‐100 thermoluminescence dosimeters. The distributions of X‐ray radiation in the energy range of 5 keV to several hundred keV were bimodal for all of the anode tips, peaked approximately at ±15°. The intensity of X‐rays decreased abruptly along the central axis of the device where the quasi cylindrical plasma pinch was formed. High intensity of X‐ray was observed in the case of a tapered ?at‐end anode, whereas less was obtained with the cylindrical hollow‐end anode. The maximum nitrogen X‐rays were for the tapered flat‐end anode at 4.5 mbar and 13 kV. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Spectrometer for hard X‐ray free‐electron laser based on diffraction focusing

X‐ray free‐electron lasers (XFELs) generate sequences of ultra‐short spatially coherent pulses of X‐ray radiation. A diffraction focusing spectrometer (DFS), which is able to measure the whole energy spectrum of the radiation of a single XFEL pulse with an energy resolution of ΔE/E? 2 × 10^?6, is proposed. This is much better than for most modern X‐ray spectrometers. Such resolution allows one to resolve the fine spectral structure of the XFEL pulse. The effect of diffraction focusing occurs in a single‐crystal plate due to dynamical scattering, and is similar to focusing in a Pendry lens made from a metamaterial with a negative refraction index. Such a spectrometer is easier to operate than those based on bent crystals. It is shown that the DFS can be used in a wide energy range from 5 keV to 20 keV.     

Comparison of calculated brightness and flux of radiation from a long‐period wiggler and a short‐period undulator

In this article the calculation of brightness and flux for two insertion devices of the 2.8 GeV X‐ray storage ring at the NSLS is discussed. The radiation properties from the X25 linearly polarized wiggler and the new X25 short‐period undulator are compared at a fixed photon energy (11.3 keV) corresponding to emission from the fifth harmonic of the short‐period undulator. For this computation, three commonly available synchrotron radiation programs are used. The capabilities of each of these codes are briefly discussed, and their range of applicability are commented on. It is concluded that special care is needed when modeling the radiation of the classes of insertion devices considered here.     

Triggering of nuclear isomers via decay of autoionization states in electron shells (NEET)

Nuclear excitation by an electron transition (NEET) may be used for triggering the decay of nuclear isomers only when there are compensations between energies (ΔE) and multipolarities (ΔL) of the nuclear transition and the transition in an electron shell. It is shown that using the autoionization states (AS) allows one to compensate for the ΔE and ΔL differences. Laser radiation may be used for the excitation of AS with energies up to 10–15 eV and ^229m Th (3.5 eV) nuclear isomer excitation by NEET via AS decay. Ion beams, electron beams, and X rays may be used for the excitation of the trigger nuclear levels with energies up to 150 keV by NEET via AS and for the triggering of the nuclear isomer decay. For excitation of AS with the energies up to 150 keV, two or more hole states in deep inner electron shells must be excited. The cross section for such two-hole state excitation in electron shells by ion beams may be sufficiently high. The possibilities of NEET via AS for the triggering of nuclear isomer decay are discussed.