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Experimental Test of 7.8GHz Power Extractor Using Dielectric Loaded Rectangular Waveguide Structures
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We report on experimental test of a 7.8 GHz power extractor using a dielectric loaded rectangular waveguide structure. This work is conducted at the Argonne wakefield accelerator (AWA) facility. The wakefield is excited by an electron beam travelling through a dielectric loaded rectangular waveguide, and the generated rf power is then subsequently extracted with a properly designed rf coupler. In the experiment, 30 MW of output power is excited by a 66nC single electron bunch, and wakefield superposition by a train consisting of four bunches is also demonstrated. Both the results agree well with theoretical predictions. 相似文献
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为了研究尾场效应引起的束流不稳定性,建立了由非对称Blumlein脉冲形成线、导体层和微堆层构成的介质壁加速器单元模块模型,用有限积分法对强流电子束在此结构中产生的尾场进行了计算,分别计算单组元和2组单元加速模块中的尾场势和尾场阻抗。从模拟的结果来看,x,y方向的尾场势和尾场阻抗都很小,束流尾场对横向的影响比较小。z方向的尾场势和尾场阻抗影响较大,尾场阻抗达到100Ω量级。证明了由于介质壁加速器结构在加速腔长度和束流通过路径的连续性方面都具有很大的优势,横向阻抗小,束流尾场效应在束流不稳定性方面的影响相对较小,束流传输时的要求也会降低。 相似文献
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为了研究尾场效应引起的束流不稳定性,建立了由非对称Blumlein脉冲形成线、导体层和微堆层构成的介质壁加速器单元模块模型,用有限积分法对强流电子束在此结构中产生的尾场进行了计算,分别计算单组元和2组单元加速模块中的尾场势和尾场阻抗。从模拟的结果来看,x, y方向的尾场势和尾场阻抗都很小,束流尾场对横向的影响比较小。z方向的尾场势和尾场阻抗影响较大,尾场阻抗达到100 Ω量级。证明了由于介质壁加速器结构在加速腔长度和束流通过路径的连续性方面都具有很大的优势,横向阻抗小,束流尾场效应在束流不稳定性方面的影响相对较小,束流传输时的要求也会降低。 相似文献
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高功率微波在受控热核聚变加热、微波高梯度加速器、高功率雷达、定向能武器、超级干扰机及冲击雷达等方面有着重要的应用.本文针对高功率微波输出窗内侧氩气放电击穿过程,建立了二次电子倍增和气体电离的一维空间分布、三维速度分布(1D3V)模型,并开发了相应的PIC/MC程序代码.研究了气压、微波频率、微波振幅对放电击穿的影响.结果表明:在真空情况下,介质窗放电击穿只存在二次电子倍增过程;在低气压和稍高气压时,二次电子倍增和气体电离共存;在极高气压时,气体电离占主导.给出了不同气压下电子、离子的密度和静电场的空间分布.此外还观察到,在500 mTorr时,随着微波振幅或微波频率的变化,气体电离出现的时刻和电离产生的等离子体峰值位置有较大差异,尤其是当微波频率(GHz)在数值上是微波振幅(MV/m)的2倍时,气体电离出现的较早. 相似文献
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本文从能量守恒定律出发,对应于等梯度加速结构,推导出瞬时束流负载一般解的解析表达式.特别对应于热阴极微波枪做为注入器的情形,此时脉冲内电流随时间线性增加,首次给出这时的束负载效应的解析公式.对北京自由电子激光器的加速器系统,给出数值计算结果,可以看到由于脉内电流的增长导致脉内束能量下降的程度. 相似文献
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S. Franchoo F. Ibrahim F. Le Blanc M. Lebois A. Olivier C. Phan Viet B. Roussière R. Sifi D. Verney 《Hyperfine Interactions》2006,171(1-3):117-119
The availability of both a tandem deuteron beam and a linac electron beam, the latter converted into Bremsstrahlung, at the
new ALTO facility at IPN-Orsay offers a unique opportunity to compare the performance of a laser ion guide under different
regimes. The ALTO accelerator has delivered its first electron beam at the end of 2005 and a design for a gas-cell prototype
is being studied. 相似文献
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D. I. Vaisburd 《Russian Physics Journal》1996,39(11):1093-1101
This article is a survey of works by the author and colleagues on the investigation of charging and discharging dynamics in
solid dielectrics exposed to dense electron beams with subnanosecond resolution. Small high-current electron accelerators
of theDzhin type, which were developed and fabricated at the Nonlinear Physics Laboratory, were used as the source of the primary electron
beam. The primary electron beam parameters were: 0.25–0.45 MeV, 1–30 nsec, 0.1–10,000 A/cm3. The dielectric is investigated experimentally with its surface covered by a metallic electrode and with critical electron
emission into the vacuum eliminated. In this case, the total current in the dielectric consists of three components: the primary
beam current, the displacement current, and the conduction current. The first and last are responsible for charging and discharging
of the dielectric volume. It is shown that the bulk nonequilibrium radiation conduction mechanism depends greatly on the dose
intensity. For small dose intensities, the principal current carriers are the low-energy electrons of the conduction band
and holes of the valence band, which are in quasi-equilibrium with the lattice phonon field before capture by defects or merging
into excitons preceding recombination. This type of conduction has been well studied in the physics of semiconductors and
dielectrics. However, over a broad interval of intermediate and high dose intensities, another type of nonequilibrium conduction
dominates — the high-energy, which was discovered and studied by the author and colleagues. The principal carriers are then
passive-ionization electrons and holes with energies of 0.1–10 eV in the process of phonon relaxation in which phonon emission
dominates absorption. The high-energy conduction differs considerably from the low-energy in many properties, which determines
the unusual dynamics of dielectric charging and discharging with irradiation by the dense electron beam of a high-current
accelerator.
Institute of High-Current Electronics, Siberian Section, Russian Academy of Sciences. Tomsk Polytechnic University. Translated
from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 109–119, November, 1996. 相似文献
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Yin Jiapeng Yuan Xiaohui Zhou Zusheng Pei Guoxi Liu Shengguang 《强激光与粒子束》2021,33(9):094003-1-094003-6
电子束在基础科学研究、工农业生产和医疗领域发挥了重要作用。提出了一种新型的电子源技术方案:高功率激光脉冲轰击金属丝靶,可以产生大量能量在百keV量级的热电子,一部分热电子在丝靶表面自生电磁场的作用下沿着丝靶运动,丝靶后方可以获得指向性良好的电子束。实验上成功在金、钨和铜丝靶后方获得了电子束团,测量了束团束斑、电荷量和能谱。铜丝靶单发实验收集到的电子束团总电荷量可达3 nC,能量分布在0~240 keV区间内,能谱在100 keV附近呈现峰值。提出了微波压缩方案,设计了2腔微波聚束腔,利用ASTRA对微波腔压缩过程进行了模拟计算。结果显示,可以将电荷量1 nC、长度55 ps的束团压缩至27 ps,满足后续微波加速器对电子源的要求。 相似文献
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介绍了介质壁加速器(DWA)的原理和几种可能实现的结构。通过对多层介质圆柱的平面波电磁散射的研究,用FORTRAN语言编写程序计算和分析了DWA加速管三层介质柱体结构的平面波电磁散射的散射宽度与几何结构参数、材料参数的关系,用以优化设计介质壁加速管结构。计算结果表明:当加速管材料和等势环介电常数一定时,平面波电磁散射宽度随半径增大而增大;当加速管内外径一定时,加速管材料和等势环介电常数增大时散射宽度变化不明显,但最小散射宽度显著减小。当加速管半径和材料一定时,总能找到使散射宽度达到最小的等势环介质厚度。 相似文献
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研究了固定式海关集装箱检测系统用9MeV电子行波直线加速器电子枪的结构特点和束流特性。该电子枪采用钪酸盐阴极,在灯丝电流为2.4A,阳极引出电压为-40kV的工作条件下,由电子枪发射到加速器入口处的脉冲电流强度为300mA,在加速器出口处,束斑截面小于φ2mm;打靶后,产生的X射线剂量率大于30cGy/(min× m)。电子枪的良好特性及束流强度保证了集装箱检测图像所需的高分辨率的要求。为保证满足更换电子枪时的安装要求,利用EGUN程序模拟计算了电子枪的结构及束流特性,为实际装配和使用提供了参考尺寸和调试参数。 相似文献
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R. H. Avagyan A. E. Avetisyan I. A. Kerobyan S. P. Taroyan A. S. Danagulyan R. M. Mirzoyan K. S. Bunyatov R. Ts. Sargsyan S. A. Galumyan V. S. Yeganov A. A. Oganesyan H. S. Vartanyan V. B. Gavalyan V. Ts. Nikogosyan V. S. Ayrapetyan A. Z. Babayan A. A. Matosyan S. V. Jamkochyan R. K. Dallakyan 《Journal of Contemporary Physics (Armenian Academy of Sciences)》2012,47(1):5-10
We describe a technique of obtaining radioactive 99mTc isotope by irradiation of molybdenum with high-intensity beam of bremsstrahlung photons from the electron beam of the linear electron accelerator (LUE50) of the Alikhanyan National Science Laboratory (ANSL, former Yerevan Physics Institute). We have elaborated and created an experimental plant for development of 99mTc production technology. Upgrading of linac has been performed aimed at raising the beam intensity and density. A system of automated control of the parameters of the plant and accelerator was built up. We carried out preliminary studies of 99mTc obtaining technique and give quantitative and qualitative results. 相似文献
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介绍了介质壁加速器(DWA)的原理和几种可能实现的结构。通过对多层介质圆柱的平面波电磁散射的研究,用FORTRAN语言编写程序计算和分析了DWA加速管三层介质柱体结构的平面波电磁散射的散射宽度与几何结构参数、材料参数的关系,用以优化设计介质壁加速管结构。计算结果表明:当加速管材料和等势环介电常数一定时,平面波电磁散射宽度随半径增大而增大;当加速管内外径一定时,加速管材料和等势环介电常数增大时散射宽度变化不明显,但最小散射宽度显著减小。当加速管半径和材料一定时,总能找到使散射宽度达到最小的等势环介质厚度。 相似文献
15.
研究了固定式海关集装箱检测系统用9MeV电子行波直线加速器电子枪的结构特点和束流特性。该电子枪采用钪酸盐阴极,在灯丝电流为2.4A,阳极引出电压为-40kV的工作条件下,由电子枪发射到加速器入口处的脉冲电流强度为300mA,在加速器出口处,束斑截面小于φ2mm;打靶后,产生的X射线剂量率大于30cGy/(min× m)。电子枪的良好特性及束流强度保证了集装箱检测图像所需的高分辨率的要求。为保证满足更换电子枪时的安装要求,利用EGUN程序模拟计算了电子枪的结构及束流特性,为实际装配和使用提供了参考尺寸和调试参数。 相似文献
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V. B. Bychkov V. S. Demidov E. V. Demidova A. N. Ermakov O. D. Ershova B. S. Ishkhanov V. P. Maslyanyi A. Yu. Sokolov N. A. Khaldeeva 《Moscow University Physics Bulletin》2007,62(3):155-159
For the first time, a detailed space-time dependence of acoustic pressure produced by a 50-MeV electron beam in water are obtained at the electron accelerator of Moscow State University. Measurements are performed at 100 points taken along one line parallel to the beam axis and spaced 6.5 cm apart from this axis. The 2D (time-distance) patterns display two paths corresponding to signals from two sound sources: a cylindrical acoustic antenna produced by the electron beam and the entrance cap separating the water and air media. 相似文献
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We report the testing of a high gradient electron accelerator with a photonic-band-gap (PBG) structure. The photonic-band-gap structure confines a fundamental TM(01)-like accelerating mode, but does not support higher-order modes (HOM). The absence of HOM is a major advantage of the PBG accelerator, since it suppresses dangerous beam instabilities caused by wakefields. The PBG structure was designed as a triangular lattice of metal rods with a missing central rod forming a defect confining the TM(01)-like mode and allowing the electron beam to propagate along the axis. The design frequency of the six-cell structure was 17.14 GHz. The PBG structure was excited by 2 MW, 100 ns pulses. A 16.5 MeV electron beam was transmitted through the PBG accelerator. The observed electron beam energy gain of 1.4 MeV corresponds to an accelerating gradient of 35 MV/m, in excellent agreement with theory. 相似文献
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Neil GR Bohn CL Benson SV Biallas G Douglas D Dylla HF Evans R Fugitt J Grippo A Gubeli J Hill R Jordan K Li R Merminga L Piot P Preble J Shinn M Siggins T Walker R Yunn B 《Physical review letters》2000,84(4):662-665
Jefferson Laboratory's kW-level infrared free-electron laser utilizes a superconducting accelerator that recovers about 75% of the electron-beam power. In achieving first lasing, the accelerator operated "straight ahead" to deliver 38-MeV, 1.1-mA cw current for lasing near 5 &mgr;m. The waste beam was sent directly to a dump while producing stable operation at up to 311 W. Utilizing the recirculation loop to send the electron beam back to the linac for energy recovery, the machine has now recovered cw average currents up to 5 mA, and has lased cw with up to 1720 W output at 3.1 &mgr;m. 相似文献