查询词典 electron beam

Those ions will perform stable oscillation nearby the beam orbit while their mass is larger than a critical mass. The accumulation of trapped ions nearby the beam orbit, interacting with beam, can cause the tune shift of beam, blowup of beam emittance, increase of local vacuum pressure, and can even lead to the occurrence of beam instability.

这些被俘获的离子在束流轨道附近的积累并和束流的相互作用，会引起束流振荡频率的漂移和展宽、束流发射度的增加、局部真空度的恶化等各种负效应，有时甚至会导致束流不稳定的发生，从而影响储存环的正常工作，在这种情况下采用离子清洗方法将离子清洗掉对保证储存环的长期、稳定的运行是必要的。

Simulative results show that the electron beam can be transported in the unmagnetized plasma-filled for two reasons. The first, the plasma neutralizes the majority of the space charge forces within the beam. The second, radial electric field generated by electron beam interaction with the plasma leads the beam to converge along axis. By PIC simulation, we find that atomic mass of the background ion effects on the Characteristics of the plasma-filled devices.

非磁化等离子体填充的RBWO-FEL的模拟表明只有在一较窄的背景等离子体密度范围内，电子注才能良好传输，产生泵波及激光功率输出，并都存在有峰值功率点，同实验观测到的结果完全吻合；该范围内，电子注的传输是由于背景离子中和了注中径向发散空间电荷力及注在等离子体中产生的径向的电场使注在轴向汇聚。

In order to use electron beam in brazing of precise structures and thermo-sensitive materials,accommodating every kinds of curve brazing seams,a vacuum electron beam brazing temperature closed loop control system was developed using PID controller,electron beam scanning track editing and on-line adjusting technologies,real-time acquisition and handling of brazing temperature.

为了将电子束应用于精密构件及热敏感性材料钎焊，以适应复杂形状曲线钎焊缝的要求，采用电子束扫描轨迹编辑及在线调节、钎焊温度实时采集及PID控制器构建真空电子束钎焊温度闭环控制系统。

Will voltage electron beam deflection plate to tie the direction switch "is" location, rotating clockwise direction deflection plate voltage Potentiometers (RP2), the electron beam is deflected upward, the greater the voltage between the deflection plate, the electron beam deflection angle the bigger.

实验一。观察电子束在电场中的偏转将电子束偏转板电压方向开关扳到&上正&位置，顺时针方向旋转偏转板电压电位器(RP2)，电子束则向上偏转，偏转板之间电压越大，则电子束偏转的角度越大。

GHz ridge－loaded helical groove slow wave structure with a 20kV electron beam are given and the investigations of the effect of the ridge dimensions and electron beam parameters on the small signal gain are carried out. It is indicated from the calculation results that this type of structure is suitable for use as s SWS of high power, high gain but narrow passband millimeter TWT, of which the 3dB gain bandwidth is 3.4%. In order to increase the bandwidth, the reduction of the ridge gap or the increase of the electron beam current in an allowable range may be useful.

GHz的脊棱加载慢波结构的具体尺寸，并对此结构中小信号增益随脊尺寸的变化情况及电子注参数对其影响进行了研究，计算结果表明：此结构适宜于作为高增益窄带毫米波大功率行波管的慢波线，其3dB增益带宽为3.4%，为了展宽其工作带宽，可以适当减小间隙宽度，也可在一定范围内提高电子注电流。

Design consideration and design methods for periodic reversal permanent magnet focusing system are presented ,special technical problems met in design of multi-beam electron gun with controlling electrode are discussed.2D computer software or magnetic field and electron trajectory of electron optics system has been established,and applied to calculate the electron optics system of S-band 200 kW multi-beam klystron.

给出了周期反转永磁聚焦系统的设计方法和设计考虑，讨论了控制极调制多注电子枪设计中遇到的特殊问题和解决方法，建立了计算电子光学系统的二维磁场和电子轨迹计算软件，并应用这些软件设计和研制了S波段200kW多注宽带速调管的电子光学系统。

It is treated with six fields (Anterior, Posterior, four obliques) positioned 60° apart around the circumference of the patient, each dual field is made up of two component beams, pointing ±15° with respect to the horizontal. The nominal energy of electron beam produced by Mevatron Ⅻ is 3MeV, and the patient is treated at a distance of 3 meters. Using Capintec dosemeter and PS-033 electron beam chamber for measurement, one moniter unit of radiation is equivalent to 0.0127cGy. Measurement of electron energy by Kodak X-omat-V verification film inside the Rando phantom at 100 cm SSD was 3.70MeV, electron energy measured at 3 meters was 3.51MeV. X-ray contamination was measured as 9.5% per six dual fields.

此种方法分别使用六个双照野，由病人的前、后、左前、右前、左后、右后各间隔60度共六个方向照射，每一双照野由水平向上和向下15度照射；荣民总医院选择3MeV电子射束来治疗病人，治疗距离为3公尺，利用擬人假体及柯达X-omat-V验证片实验得电子射束初始能量从3.7Mev变为3.51MeV，六个双照野之X光污染共达9.5%，使用Capintec剂量表及PS-033型电子射束用游离腔测量六个双照野，每一监测单位相当於0.00127 cGy。

Variation laws of electron movement with emergence angle and microwave electromagnetic parameters are also derived. The emergence angle of electron has significant effect on the movement of electron, and there is an emergence angle in which the electron has the maximum trajectory length and impact energy, Impact energy will increase and return time will reduce as increasing the amplitude of electric field, and both parameter would oscillate with the phase of electric field, which can essentially explain that multipactoring electron number oscillates in twice the frequency with the increase of microwave frequency, electron trajectory will change from parabolic-like movement to complex oscillation.

研究发现：电子出射角度对其运动状态有显著影响，电子存在运动轨迹最大的某一出射角度，该角度下电子拥有最大的撞击能量；微波电场幅值的增加将使电子撞击能量增加，返回时间减小，微波电场相位的变化使电子的撞击能量和返回时间呈周期振荡，这从本质上解释了电子数量在二次电子倍增过程中以微波频率两倍周期振荡的原因；随着微波频率的增加电子将由简单的类抛物线运动转变为复杂的振荡运动。

In chapter 2 and 3, experimentally, using the Angular-Resolved high-resolution fast Electron Energy Loss Spectrometer , at the condition of 2. 5 keV incident energy and 50-60 meV energy resolution, we measured the Optical Oscillator Strength Density Spectra for the excitations of 4p, 4s or 3d electron. The oscillator strengths for excitations of the valent shell 4p electron were obtained, and comparisons were done between presently experimental and previously experimental and theoretical results. The experimental results of different groups agree with each other approximately, but the semi-experientially theoretical results do not match with the experimental results. The delayed maximum in the photoabsorption spectra was discussed. It should arise from the transition of 4p→∈d. For the excitation of the inner-valent 4s electron, the discrepancies for the resonant structures in previous electron-impact results and photoionization results were clarified in present work, which confirms again that the fast electron impact method is suitable to measure the optical oscillator strengths. The autoionization Rydberg series 4s〓ns (n=5, 6, 7) and 4s〓nd (n=4, 5, 6, 7) were identified without ambiguity by the measurement at 0°, 2° and 4°scattering angles. The energy levels and natural widths of the excitations of Kr3d and Ar2p inner shell, including optically allowed and forbidden transitions, were determined. The widths of these inner shell excitations are nearly the same, which was interpreted by the Resonant Auger effect .

在第二章和第三章，实验上，使用角分辨的高能量分辨快电子能量损失谱仪，在2.5keV电子入射能量和50-60meV能量分辨下，测量了Kr原子由价壳层4p到内价壳层4s，再到内壳层3d电子激发的光学振子强度密度谱；得到了价壳层4p电子激发束缚态的光学振子强度，与前人实验和半经验理论结果作了细致的比较，说明几家实验是比较符合的，但半经验的理论计算存在问题；分析了光吸收谱中的延迟极大现象，说明在第一电离阈值以上几个eV范围内的极大值源于4p→εd跃迁产生的延迟极大；对于内价壳层4s激发的自电离区，澄清了前人实验中电子碰撞方法和光学方法在共振结构上存在差异的问题，再一次肯定了快电子碰撞方法是获得绝对光学振子强度的一种好方法；通过在非0°散射角的测量（如2°和4°），清楚地标识了4s电子激发的光学禁戒跃迁自电离里德堡系列4s〓ns（n=5，6，7）和4s〓nd（n=4，5，6，7）；通过在0°和4°散射角的测量，观测并标识了几个新的内壳层光学禁戒跃迁能级，得到了Kr原子3d和Ar原子2p内壳层激发态（包括光学允许和禁戒跃迁形成的）的能级位置和自然宽度，用共振俄歇效应解释了这些内壳层激发态（不管是光学允许还是禁戒跃迁产生的）的自然宽度彼此比较接近的原因。

Five novel torsion-mirror optical actuators including double-beam thickness differential structure with single torsional axis, double flexible folded-beam structure with single torsional axis, double-beam vertical torsion comb structure with single torsion axis, four-beam differential compound-micromirror structure with double torsional axis and the combined structure of the four basis forms above, are brought forward. All of these devices could be fabricated by the same silicon micromachining process we have developed. The deformation compensation design with local enhancement for the thin torsional beam which is the key structure of these devices is also put forward to improve the reliability. The three-dimension solid model and two-dimension reduced order model of the torsion-mirror optical actuator are established and then the numerical simulations for evaluating the device characteristics of the statics, dynamics, electrostatic field, mechanical and electrostatic coupling, fluid and solid coupling are carried out to optimize the structure design. Furthermore, three optical fibre clamping structures which could be integrated monolithicly are designed and analyzed to improve the optical coupling capability. 4. Three flexible process flows combined with bulk silicon micromachining and surface silicon micromachining are brought forward to fabricate these novel single-crystal silicon or polysilicon torsion-mirror optical actuators by using the same lithography masks for both SOI wafer and regular silicon wafer. A series of important process experiments are carried out to optimize the process parameters and the process flows. Some novel and typical process phenomena which occurred during the microfabrication are analyzed and then the corresponding solutions are put forward. 5. A MEMS dynamic testing system which exploit blur image synthetic technique, stroboscopic image matching technique, stroboscopic mirau microscopic interferometry technique and microscopic laser dopper vibrometer technique is set up to measure three-dimension and six-freedom micro motions of any MEMS devices with nanometer resolution.

在对硅微机械扭转镜光致动器的光机电特性系统地理论研究的基础上提出了硅微机械扭转镜光致动器的结构设计准则。3、提出了单轴双梁厚度差分结构、单轴双柔性折叠梁结构、单轴双梁垂直扭转梳齿结构、双轴四梁差动复合微镜结构以及以上四种基本结构组合后的衍生结构等五种工艺加工技术兼容的新型的硅微机械扭转镜光致动器，对器件关键结构薄厚度、高耐疲劳扭转梁进行了局部加强的变形补偿设计，建立了器件的三维实体模型以及两维降阶模型，对提出的新结构硅微机械扭转镜光致动器进行了系统的静力学、动力学、静电场、力电耦合和流体固体耦合的建模仿真与优化设计，同时设计并分析了三种可实现单芯片集成的弹性光纤定位夹紧结构。4、提出了组合体硅微加工技术与表面硅微加工技术、兼容同一套光刻版图、可分别基于SOI 晶片和普通Si 晶片、适应于制造提出的各种新结构单晶硅和多晶硅硅微机械扭转镜光致动器的三套柔性加工工艺流程，开展了一系列重要工艺步骤的单项工艺试验，对工艺流程与工艺参数进行了优化，针对加工过程中出现的具有普遍意义的典型工艺问题进行了讨论和分析，并提出了解决方法。5、创新性地将模糊图像合成技术、频闪图像匹配技术、频闪Mirau 显微干涉技术与显微激光多普勒测振技术有机结合，建立起了一套周期运动测量与瞬态运动测量相结合、单点运动测量与全视场运动测量相结合、满足不同MEMS 器件各种动态测试要求的集成的MEMS 三维六自由度微运动精密测量系统。

This paper designs the communication system of radio telescope FAST.

针对500m口径球面射电望远镜FAST分布式控制系统的特点完成了其通信系统的设计。

Political sheep's step-by-step a large number of fossils unearthed in the county soil Ma Ali after rural village in the middle of sallow pelitic siltstone.

步氏和政羊化石大量出土于广河县阿力麻土乡后山村，产于灰黄色泥质粉砂岩中。