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Hyoung Suk Kim Saeyoung Ahn 《International Journal of Infrared and Millimeter Waves》2000,21(1):11-20
A klystrode oscillator cavity is designed using annular electron beam in the C-band frequency that can be easily scaled to S and X bands. Beam electrons are assumed pre-modulated and injected into the toroidal cavity in the shape of thin reentrant resonator with the grid structure built in the beam entrance. We optimize the beam conversion efficiency via the MAGIC code in the range of sixty to seventy percent with the fundamental TM01-mode which is fine tuned by the 3D HFSS code. The annular electron beam has a merit to permit the center coupling to the adjacent cavity to enhance and stabilize the beam pre-modulation in addition to increased power handling capability. 相似文献
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基于电场递增效应理论,讨论了多极板赝火花脉冲电子束的特征.通过电子束对固体变色片和金属靶的轰击,对赝火花电子束的不稳定性、细丝效应和自箍缩效应等现象做了研究和分析.The characteristics of pulsed electron beam generated by multiplate pseudospark chamber (MPC) on the basis of field escalation effects have been described in this paper. The phenomena such as instability, filament effect, and self-pinch effect of pseudospark electron beam were studied and analyzedby the bombardment of solid evident films and metal targets. 相似文献
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Ming Chang Wang Chi Yang Byung Cheol Lee Jongmin Lee 《International Journal of Infrared and Millimeter Waves》1999,20(10):1739-1748
A guided field is an important part for focusing the intense beam in Raman free electron laser. A new electron beam source with high brightness of 1012A/(m rad)2 based on a pseudospark discharge was developed [1]. Numerical simulation showed that the guided field for compact free electron lasers could be removed using the new beam source. An electron beam with 12 kA current and 300 kV voltage was obtained. Self-pinch effect of high current beam was observed, the beam propagates 75 cm with constant diameter of 1.5 mm without guided field. 相似文献
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电子束辐照技术在剩余污泥处理应用中具有巨大潜能。大量研究表明,经高能电子束辐照,污泥中的各种病原菌会有不同程度的死亡、有机物( 包括非生物降解物质) 大量分解、脱水率提高,臭味减少,危害性降低和资源化应用潜能增加。综述了电子束辐照技术在剩余污泥处理中的优势,重点介绍该技术的应用现状、污泥中污染物的去除机理、处理效果和相关建设费用,并展望了该高新技术的应用前景和发展方向。Recently, electron beam irradiation has great potential in dealing with excess sludge . A great deal of studies showed that the electron beam irradiation played an enormous role in promoting the sludge harmless treatment. Most of pathogenicbacteria was dead and lots of organic substances, especially some non-biodegradable ones, were decomposed by the high electron beam irradiation. The irradiated sludge also had low water content, less odour, low hazard and a better application potential in utilization. This paper reviews the application of electron beam irradiation on excess sludge, the advantages and current situation of the irradiation technology. Mechanisms of removing contaminants, effects of treatment and the construction expense are mainly discussed. The future development of this advanced technology areprospected finally. 相似文献
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Electron beam density imaging system at Beam study using a portable slit the Shanghai Electron Ion Trap
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Yang Yang Lu Di Pu Yun-Qing Yao Ke Chen Wei-Dong Xiao Jun Geng Zhi-Xian Roger Hutton Zou Ya-Ming 《中国物理 B》2011,(8):136-142
In this work, a portable slit imaging system is developed to study both the electron beam diameter and the profile of the newly developed Shanghai Electron Beam Ion Trap (Shanghai EBIT). Images are detected by a charge coupled device (CCD) sensitive to both X rays and longer wavelength photons (up to visible). Large scale ray tracings were conducted for correcting the image broadening effects caused by the finite slit width and the finite width of the CCD pixels. A numerical de-convolution method was developed to analyse and reconstruct the electron beam density distribution in the EBIT. As an example of the measured beam diameter and current density, the FWHM (full width at half maximum) diameter of the electron beam at 81 keV and 120 mA is found to be 76.2 μm and the density 2.00 × 10^3 A.cm-2, under a magnetic field of 3 T, including all corrections. 相似文献
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Electron beam density study using a portable slit imaging system at the Shanghai Electron Beam Ion Trap
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In this work,a portable slit imaging system is developed to study both the electron beam diameter and the profile of the newly developed Shanghai Electron Beam Ion Trap (Shanghai EBIT).Images are detected by a charge coupled device (CCD) sensitive to both X rays and longer wavelength photons (up to visible).Large scale ray tracings were conducted for correcting the image broadening effects caused by the finite slit width and the finite width of the CCD pixels.A numerical de-convolution method was developed to analyse and reconstruct the electron beam density distribution in the EBIT.As an example of the measured beam diameter and current density,the FWHM (full width at half maximum) diameter of the electron beam at 81 keV and 120 mA is found to be 76.2 μm and the density 2.00 × 10 3 A·cm 2,under a magnetic field of 3 T,including all corrections. 相似文献
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高能电子束对抗蚀剂曝光的Monte Carlo模拟 总被引:1,自引:0,他引:1
利用分段散射模型, 借助Monte Carlo方法模拟了具有高斯分布特征的
高能入射电子束(50keV≤E0≤100keV)在抗蚀剂中的
散射过程, 分别得到了不同曝光条件下的电子背散射系数和能量沉积分布,
模拟结果与实验结果很好地符合. 在这一能量段, 当电子束能量越高、抗蚀剂
越薄、基片材料的原子序数越低时, 邻近效应越弱. 本文的模拟结果不仅能为高能电子束光刻工艺优化曝光条件、降低邻近效应提供理论指导, 而且能为进一步的邻近效应的校正提供更精确的数据. 相似文献
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聚四氟乙烯密封材料的电子束辐射效应研究 总被引:2,自引:0,他引:2
采用低能电子束辐射系统地研究了操作氚系统用密封材料(聚四氟乙烯)的辐射效应。利用扫描电镜和X光电子能谱仪分析了材料的表观形貌和表面元素的变化,用X射线粉末衍射仪和热分析仪分析了辐照前后材料的结晶度改变和热稳定性程度,并利用气相色谱仪和质谱仪测定了辐射降解气体的成分和生成量随吸收剂量的变化规律。采用电子自旋共振谱仪研究了材料在辐照过程中产生的中间体(自由基),利用正电子湮没寿命谱仪分析了材料中的自由体积孔洞及浓度。结果表明,辐照前聚四氟氟乙烯样品的表面是规则的带状晶形结构,经1×10^5Gy辐照后样品的晶状结构遭到了明显的破坏,向非晶态转变显著。辐照后样品的熔点和热分解温度均呈下降趋势,表明样品的热稳定性降低。聚。四氟乙烯材料在氧气气氛中发生的辐射降解最为严重,其次是真空,而在氘气气氛中辐射降解最少。材料的辐射降解主要发生在主链上,即C—C键断裂,而侧基C—F键的断裂相对较少。第三寿命强度I3的变化规律与τ3相反,即随吸收剂量的增大,第三寿命的强度I3降低,表明自由体积孔洞的浓度降低。 The radiation effect of polytetrafluoroethylene used as a kind of sealing material in the tritium system was studied by using electron beam. The superficial configuration and state were analyzed by SEM and XPS respectively, and the crystal degree and thermal stability were determined by XRD and DSC. At the same time the composition of gas products after radiation ,was measured by GC/MS, and the yield of CO2 with the dose increasing was analyzed. The free radicals produced in the process of radiation were studied by ESR, and the content of free volume of PTFE is analyzed by positron annihilation lifetime spectroscopy. The result is that the crystal structure of the sample irradiated at the dose of 1 × 10^5 Gy is of an obvious damage while the structure of the unirradiated sample is crystal band. The transformation of the sample which has high crystal degree amorphous one. The melting point and thermal ecomposition temperature trend sample's thermal stability drops. The radiation decomposition of the sample is is remarkable from crystal state to to decline, which indiccates that the mainly the rupture of C--C bond, and less is the rupture of C--F bond. The Intensity I3 of the third lifetime fails with increasing the absorbed dose, which demonstrates the reduction of free volume cave content. Compared with I3, the rule of τ3 is reverse. 相似文献
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在中国科学院近代物理研究所自行研制的大功率电子加速器上, 研究了不同辐照剂量的电子束对大肠杆菌、 金黄色葡萄球菌和变形杆菌3种微生物的杀灭效果, 同时检测了辐照后菌体超氧化物歧化酶(SOD)活性的变化。 结果显示: 辐照剂量达到2.0 kGy时, 可完全杀灭金黄色葡萄球菌, 2.2 kGy时可完全杀灭大肠杆菌和变形杆菌; 辐照对3种微生物的SOD活性有较显著的影响。 To study the effects of radiation sterilization of the electron beam, the three species of microorganisms, Escherichia. coli, Staphylococcus aureus and Proteus vulgaris were irradiated with the electron beam, delivered by the electron accelerator independently developed by the Institute of Modern Physics, Chinese Academy of Sciences, and the changes of superoxide dismutase (SOD) activity of these irradiated microorganisms were also tested. The results indicated that the Staphylococcus aureus were fully radio sterilized with the radiation dosage of 2.0 kGy, but 2.2 kGy to the Escherichia.coli and Proteus vulgaris. Moreover, the data also demonstrated that the irradiation had noticeable effects on the SOD activity of the three microorganisms. 相似文献
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In this paper, the coupling instability of warm relativistic electron beam (WREB) propagating through the ion channel guiding is investigated in detail. Obtaining the equilibrium state of the system by considering the self-electric and azimuthal magnetic field, the fluid-Maxwell equations as well as linear perturbation theory are employed to derive the dispersion relation of the excited modes in the system. Numerical analysis of the obtained dispersion relation shows that the electromagnetic (EM) instability can be induced nearly the center of the beam through coupling between the fast electron plasma wave (FEPW), originated from the longitudinal oscillation of WREB, and fast forward electromagnetic wave (FFEW). In this sense, growing the perturbation amplitude occurs due to transport the kinetic energy of WREB to the EM wave at the specific frequency range, where the phase velocity of FEPW and FFEW is coincided. The results of the present investigation will greatly contribute to the understanding of the stability of the warm relativistic electron beam in laboratory experiments, such as in free electron laser experiments, where the ion-channel guiding is used to confine the electrons against the self-repulsive forces generated by the beam itself. 相似文献
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新型电子束源—虚火花放电室设计 总被引:1,自引:0,他引:1
提出一种新型的脉冲线加速器驱动的高功率,强流密度,低发射率,高亮度电子束源-虚火花放电室的初步设计。基于空心阴极效应和虚火花放电经验公式,确定了空心阴极,多隙阴-阳极,取及工作气压范围,最后提出关于虚火花产生高亮度电子束源的总体实验方案。 相似文献
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The modulational instability of ion-acoustic wave in a collisionless, unmagnetized plasma consisting ofwarm ions, hot isothermal electrons, and relativistic electron beam is studied. A modified nonlinear Schrodinger equationincluding one additional term that comes from the effect of relativistic electron beam is derived. It is found that theinclusion of a relativistic electron beam would modify the modulational instability of the wave packet and could notadmit any stationary soliton waves. 相似文献
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采用不同材质的刻槽绝缘平行板,包括高纯度石英玻璃、聚四氟乙烯(Teflon)、酚醛树脂(电木)和聚甲醛板(赛钢板),并在15 pA/mm2 ~14.3 nA/mm2范围内改变入射流强,利用1 500 eV电子束入射上述绝缘平行板,实验研究了上述平行板对电子束的导向行为。实验发现,上述电子束通过上述平行板时存在明显的导向现象,其导向行为与束流流强和绝缘材质无关。据此,可排除绝缘平行板内表面沉积电荷自组织充放电过程中,以绝缘材料的面电阻和体电阻对地泄放的线性形式放电过程。Adopting several grooved parallel plates made by different insulators, such as high-purity fused quartz, Teflon, Bakelite and POM (Polyformaldehyde), and further adjusting the electron beam current in a wide range (tens of pA~tens of nA), the discharging mechanism in the self-organizing charge and discharge processes of electron guiding was investigated and discussed by using 1 500 eV incident electron beam. The present results show that, the electron guiding behaviors are obviously existing when such electron beam is transmitted through the above grooved insulating parallel plates, which are independent on beam current and insulators. Our results suggest that, the possibilities of the accumulated charges on inner-surface of grooved parallel plates linearly discharging through surface and bulk resistances of plates into the ground should be excluded. 相似文献
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随着高能物理的发展, 高能量正负电子对撞机, X射线自由电子激光器, 先进的同步光源等, 都需要产生高流强超短脉冲的相对论电子束团. 于是, 亚皮秒电子束束团诊断成为加速器物理新发展的关键技术, 电子束长度的监测是其中的一部分. 电光采样(EOS)法测量超短电子束团长度有非侵入、非破坏、实时测量的特点, 具有较好的应用前景. 本文介绍该方法的原理, 通过模拟计算分析电子束束团与探测光间距、电子束电场与电光晶体晶轴夹角、探测光偏振方向与电光晶体晶轴夹角等实验参数与束团长度测量的关系, 做系统误差分析, 对实际实验有指导意义. 相似文献