共查询到20条相似文献,搜索用时 31 毫秒
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Haworth M.D. Baca G. Benford J. Englert T. Hackett K. Hendricks K.J. Henley D. LaCour M. Lemke R.W. Price D. Ralph D. Sena M. Shiffler D. Spencer T.A. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1998,26(3):312-319
The Air Force Research Laboratory/Phillips Laboratory magnetically insulated transmission line oscillator (MILO) is a gigawatt-class, L-band, high-power microwave tube driven by a 500-kV, 60-kA electron beam. A previous version of this tube generated 1.5 GW pulses, but with significant RF pulse shortening, The paper reports on improvements to the tube that have allowed us to increase the output power by 25% and to increase the RF pulse duration by a factor of two and a half 相似文献
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研制了一种用于磁绝缘传输线(MITL)电压测量的自积分式电容分压器;利用PSpice软件和标定实验数据,建立了该分压器等效电路模型,给出了分压器系统传递函数,并分析了分压器频率响应特性。计算结果表明:该分压器对于被测信号大于5 MHz频率分量部分的相频和幅频响应无明显畸变。基于强光一号长1.0 m、阴阳极间隙2 cm的同轴型MITL实验平台对该分压器实际工作性能进行了考核。实验结果表明,在相对少量场致发射电子抵达阳极表面的条件下,该分压器能够有效测量MITL沿线电压波形(2.07 负载条件下,电压峰值约600 kV、峰值时间约80 ns)。 相似文献
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研制了一种用于磁绝缘传输线(MITL)电压测量的自积分式电容分压器;利用PSpice软件和标定实验数据,建立了该分压器等效电路模型,给出了分压器系统传递函数,并分析了分压器频率响应特性。计算结果表明:该分压器对于被测信号大于5 MHz频率分量部分的相频和幅频响应无明显畸变。基于强光一号长1.0 m、阴阳极间隙2 cm的同轴型MITL实验平台对该分压器实际工作性能进行了考核。实验结果表明,在相对少量场致发射电子抵达阳极表面的条件下,该分压器能够有效测量MITL沿线电压波形(2.07 负载条件下,电压峰值约600 kV、峰值时间约80 ns)。 相似文献
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Rosenthal S.E. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1991,19(5):822-830
The operation of the linear-induction accelerators HELIA and Hermes III was studied in both negative and positive polarities. The experiments in positive polarity have provided a unique opportunity to explore the consequences of multiple-cathode electron emission in magnetically insulated transmission lines. It is maintained that an examination of the total energy-canonical momentum distribution of the electrons explains the features of the magnetically insulated flow exhibited by these systems. Simple analysis based on the basic concept of pressure balance, in conjunction with particle-in-cell numerical simulations, shows how the line voltage is related to the anode and cathode currents. Two flow designations are introduced that can apply to multiple-cathode, magnetically insulated transmission lines: full-gap flow (FGF) and locally emitted flow (LEF) 相似文献
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The effect of ions in a magnetically insulated crossed-field gap is studied using a single particle orbit model, shear flow model, and particle-in-cell simulation. It is found that, in general, the presence of ions in a crossed-field gap always increases the electrons' excursion toward the anode region, regardless of the location of the ions. Thus, the rate at which the electrons migrate toward the anode, which is a measure of the diode closure rate, is related to the rate at which ions are introduced into the crossed-field gap. This anode migration of electrons is unrelated to crossed-field ambipolar diffusion. The implications of these findings are explored, such as pulse shortening in relativistic magnetrons and bipolar flows in pulsed-power systems. 相似文献
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理论分析了二极管磁绝缘传输线(MITL)区阻抗不连续和二极管阻抗随时间的变化对波过程的影响。结果表明:若MITL区电长度远小于入射波脉宽,则二极管前端测得的电压电流幅值反映了阴极处电压、电流,电压与电流的比值由二极管阻抗确定;为加快阴极处电压、电流前沿,MITL区各段传输线沿波的传输方向可采用阻抗渐增的方式,且取中间元件的阻抗为其两端元件阻抗的均方根;测点电压、电流前沿在时间上可分为传输、全反射和束流形成阶段;梯形电压波入射下,测点波形前沿全反射阶段电压较传输阶段增长速度倍增,电流为一段平台;实际电压波入射下,测点电压波形前沿为一条不断增长的曲线,电流波形前沿存在振荡。 相似文献
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对一种由弱变和强变结构组成的锥形磁绝缘线振荡器进行了长脉冲实验研究。在二极管电压350 kV左右、电流约25 kA、脉宽约128 ns的条件下,获得了500 MW、脉宽约90 ns的高功率微波输出。对波形中出现的拐点进行了分析,研究表明:二极管电压波形好坏会对微波源的性能造成严重的影响,较好的电压波形是实现长脉冲运行的关键。同时对采用不锈钢平面负载、不锈钢丝网状负载以及石墨负载电子收集极进行了实验研究,研究表明采用石墨收集极可以输出较好的微波波形。 相似文献
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Swegle J.A. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1996,24(5):1277-1284
The study of magnetically insulated electron flow is a topic of relevance to the startup state of magnetrons, cross-field amplifiers, and magnetically insulated line oscillators, as well as to the operation of magnetically insulated transmission lines and ion diodes. In a recent paper, Christenson and Lau explored double-stream equilibria in magnetically insulated diodes analytically for the case of vanishing injection electron velocities at the cathode and numerically for the case of nonzero injection velocities. Here, the analytical results are generalized to the case of nonzero injection velocities to allow the calculation of the equilibrium current density and electron sheath thickness as functions of the voltage, magnetic field, and gap width. An interesting outcome of the analysis is that it is shown that space-charge limited electron emission from the cathode is no longer possible for equilibria in which the electrons are monoenergetic with vanishing canonical momenta. In addition, for the special case of zero injection energies, but not necessarily zero electric field at the cathode, closed-form expressions are derived for the orbital quantities of the electrons-positions and velocities-as a function of time measured from the moment of emission from the cathode. Unfortunately, a spatial variation is not apparently available in closed form; however, one can express these quantities alternatively in terms of a generalized potential with an implicit spatial variation 相似文献
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Observations of Neutral Impurity Emission during Operation of Intense Pulsed Ion and Electron Diodes
The number of neutral particles (N) emitted during the pulsed operation of two magnetically insulated ion diodes and a typical electron diode were measured with an ionization technique. Among the factors that were found to affect the total number of emitted neutrals were the elapsed time between consecutive firings and the power of the voltage pulse. A typical value of N for the electron diode operating at approximately 300 kV and 80 kA was 1019, while values of N for the ion diodes operating in the 90-320 kV range were 3-30 times greater. 相似文献
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对一种由弱变和强变结构组成的锥形磁绝缘线振荡器进行了长脉冲实验研究。在二极管电压350 kV左右、电流约25 kA、脉宽约128 ns的条件下,获得了500 MW、脉宽约90 ns的高功率微波输出。对波形中出现的拐点进行了分析,研究表明:二极管电压波形好坏会对微波源的性能造成严重的影响,较好的电压波形是实现长脉冲运行的关键。同时对采用不锈钢平面负载、不锈钢丝网状负载以及石墨负载电子收集极进行了实验研究,研究表明采用石墨收集极可以输出较好的微波波形。 相似文献
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V. M. Bystritsky Vit. M. Bystritsky G. N. Dudkin B. A. Nechaev V. N. Padalko 《Physics of Particles and Nuclei》2017,48(4):659-679
The factors defining the constraints on the current characteristics of the magnetically insulated ion diode (IDM) are considered. The specific current parameters close to the maximum possible ones are obtained for the particular IDM-40 design assigned for acceleration of light ions and investigation of nuclear reactions with small cross sections in the astrophysical energy range (2–40 keV) in the entrance channel. It is experimentally demonstrated that the chosen optimal operation conditions for IDM-40 units provide high stability of the parameters (energy distribution and composition of accelerated particle beams, degree of neutralization) of the accelerated particle flux, which increases during the working pulse. 相似文献
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We have performed experiments using magnetically insulated transmission. lines (MITL's) with anode-cathode gaps ranging from 0.15 to 0.40 cm. We have studied cathode plasma formation using laser schlieren photography, time resolved visible photography, and visible spectroscopy. Cathode plasma formation occurs within 10 ns of the application of the voltage pulse. Densities of 1015 cm-3-1017 cm-3 are inferred from the schlieren measurements. Negative ion formation in MITL's has also been observed which may result in losses in high-current-density small-gap power feeds. 相似文献
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从层流模型出发,根据线电压和线电流,给出了磁绝缘稳态时传输线极间的电磁场分布的解析表达式。在此基础上,计算了考虑空间电子效应后处于磁绝缘稳态的传输线等效分布电感和电容,以改进磁绝缘稳态的电路单元模型。利用该方法,模拟计算了Z加速器的MITL-A在磁绝缘稳态时的等效分布电感和电容。结果表明,等效分布电容随空间电子效应的增强而变大,而等效分布电感随空间电子效应的增强而变小;且线电压越低,等效分布电感和电容随空间电子效应的增强变化越快。 相似文献
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Recent work on pulsed cryogenic ion sources at the Tokyo Institute of Technology are reviewed briefly. Surface flashover processes of low-temperature dielectric materials are investigated experimentally in connection with the cryogenic ion sources. Values of dc or pulse breakdown voltage are measured, and fast-frame photographs are taken to observe the luminous surfaces. Characteristics of magnetically insulated cryogenic diodes with externally applied radial fields are clarified as a function of the anode temperature. Hydrogen, nitrogen, or argon ion beam is extracted from each ice on the anode surface of the cryogenic diode. 相似文献