Propagation of a magnetic insulation wave in a vacuum line with a bias current

An analytic model is developed and numerical simulation is performed for the operation of a vacuum coaxial line with a bias current. The results of computations make it possible to determine the bias current preventing electron leakage at the front of an incident voltage wave and to predict the ??hot?? line impedance. This model forms the basis of the method for determining the voltage across a vacuum load with the help of a short-circuited coaxial line with a bias current.     

Retrapping of current in a vacuum transmission line upon reflection of a magnetic self-insulation wave from a load

The equations derived in the framework of the Brillouin model of an electron layer in a “hot” vacuum transmission line form the basis for analysis of reflection of an electromagnetic wave from a load, leading to a redistribution of currents in the magnetically insulated transmission line (MITL). It is shown theoretically for the first time that conversion (retrapping) of a considerable fraction of the current in the electron layer to the cathode current upon the reflection of the wave from the load upon an insignificant change in the current and voltage in the line is possible even under the conditions close to the self-consistent regime. This effect can be explained by the change in the state of the electron layer under the action of the reflected wave, which is associated with a transition of the system from the right branch of the magnetic self-insulation curve to the left branch.     

Invariance analysis and conservation laws of the wave equation on Vaidya manifolds

In this paper we discuss symmetries of classes of wave equations that arise as a consequence of some Vaidya metrics. We show how the wave equation is altered by the underlying geometry. In particular, a range of consequences on the form of the wave equation, the symmetries and number of conservation laws, inter alia, are altered by the manifold on which the model wave rests. We find Lie and Noether point symmetries of the corresponding wave equations and give some reductions. Some interesting physical conclusions relating to conservation laws such as energy, linear and angular momenta are also determined. We also present some interesting comparisons with the standard wave equations on a flat geometry. Finally, we pursue the existence of higher-order variational symmetries of equations on nonflat manifolds.     

激光脉冲放大器传输波的计算

研究了一个非线性激光脉冲放大器传输系统，利用广义泛函-变分迭代理论和方法，得到了相应系统的近似解.从而为设计激光脉冲放大器提供了便利. 关键词： 激光 放大器 非线性     

Influence of the vacuum magnetic moment on the induced radiation of an electron in a plane wave

Expressions are obtained for the probability and intensity of induced radiation from an electron with a vacuum magnetic moment moving in a plane electromagnetic wave of small amplitude. The wave is supposed to be monochromatic and to have random polarization. The results of previous publications on this subject [4–6] are included here as special cases.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 51–54, August, 1972.     

Modeling the wave parameters of a narrow slotted transmission line based on a superconducting film

An analytical expression for calculating the wave parameters of a narrow-slot transmission line is found in the quasistatic approximation. A two-fluid model is used for analyzing processes in a superconducting film of thickness comparable to the London penetration depth. The wave parameters of the slotted line are calculated under assumptions about the current distribution near the edges of the slot which are analogous to those used previously for analyzing microstrip and coplanar lines. Zh. Tekh. Fiz. 67, 94–97 (September 1997)     

真空传输线板-锥过渡结构的功率流分析

真空传输线板-锥转角过渡是多模块汇流的Z箍缩装置经常采用的结构,在不考虑磁绝缘失效、介质损耗的前提下,采用有限差分方法分析转角过渡对功率流传输的影响。初步的计算和分析表明:随着转角的变大,由阻抗不匹配引起的反射将使传输效率有所降低;前沿较陡的快脉冲在这种结构中发生严重畸变,而低频脉冲则几乎不受影响。在板-锥过渡设计中采用小转角结构,尽量减小脉冲传输方向的变化,对保证脉冲高效传输有利。     

真空传输线板-锥过渡结构的功率流分析

真空传输线板-锥转角过渡是多模块汇流的Z箍缩装置经常采用的结构,在不考虑磁绝缘失效、介质损耗的前提下,采用有限差分方法分析转角过渡对功率流传输的影响。初步的计算和分析表明:随着转角的变大,由阻抗不匹配引起的反射将使传输效率有所降低;前沿较陡的快脉冲在这种结构中发生严重畸变,而低频脉冲则几乎不受影响。在板-锥过渡设计中采用小转角结构,尽量减小脉冲传输方向的变化,对保证脉冲高效传输有利。     

Compact envelope dark solitary wave in a discrete nonlinear electrical transmission line

We introduce an extended nonlinear Schrödinger (ENLS) equation describing the dynamics of modulated waves in a nonlinear discrete electrical transmission line (NLTL) with nonlinear dispersion. We show that this equation admits envelope dark solitary wave with compact support, with width and speed independent of the amplitude, as a solution. Analytical criteria of existence and stability of this solution are derived. In particular, we show that the modulated compact wave may exist in the NLTL depending on the frequency range of the chosen carrier wave, for physically realistic parameters. The stability of compact dark solitary wave is confirmed by numerical simulations of this ENLS equation and the exact equations of the network.     

磁芯对螺旋线放电波过程的影响

提出了采用渐开线硅钢叠片的变压器磁芯与螺旋线的一体化的长脉冲产生结构;计算了螺旋线引入磁芯后,电磁波延迟传输的慢波系数和波阻抗参数,以及脉冲形成的输出参数,并开展了数值模拟进行验证。研究结果表明：引入磁芯后,螺旋线上慢波传输时,内外筒电流沿磁芯基底而非磁芯表面;磁芯的径向厚度相对磁芯径向尺寸越小,磁芯对脉冲形成的影响越小。     

磁场对四端量子波导中电子输运性质的影响

采用模匹配方法，研究了非均匀磁场下开放的四端量子波导中的电子输运性质. 结果表明，从一端入射的电子可以透射到两个与之垂直的输出端和一个与之平行的输出端. 在没有外加磁场的情况下，两个垂直输出端的输运概率是相同的，但垂直端与水平端的输运概率不同；在外加磁场下，由于磁边缘态效应，两个垂直输出端的输运概率也有着相当大的差别. 通过施加不同的磁场，我们能获得丰富的电子输运结构，如台阶，宽谷，尖峰等；通过调节磁场的大小和比例以及结构参数可控制该量子结构在各输出端的输运概率. 关键词： 电子输运 介观体系 磁效应     

Motion and radiation of an electron exhibiting a vacuum magnetic moment in the field of a plane electromagnetic wave

A study is made of the motion of an electron exhibiting an anomalous magnetic moment and moving in the field of a plane circularly polarized electromagnetic wave. An exact solution is found to the generalized Dirac equation and is utilized to study the emission of electromagnetic radiation from the electron (the Compton effect). It is shown that allowance for the anomalous magnetic moment of the electron leads to: a frequency shift, a change in the total radiated power, polarization of the radiation, and to spin effects.     

Generation of high-frequency oscillations by electromagnetic shock wave on transmission lines on the basis of multilayer heterostructures

The possibility of the direct effective transformation of a videopulse into a radiopulse with high filling frequency (of the order of 100÷300 GHz) because of evolution of an electromagnetic shock wave structure on dispersive transmission lines with nonlinear components on the basis of multilayer heterostuctures (MLHS) with hysteretic (asymmetric MLHS) and single-valued functional (symmetric MLHS) capacitance — voltage characteristics has been investigated. The requirements on the MLHS and dispersion characteristics for effective generation of the train of oscillations are discussed.     

Renormalization of the two-photon vacuum polarization and the self energy vacuum polarization for a tightly bound electron

The renormalization method of Bogoljubov-Parasiuk-Hepp-Zimmermann (BPHZ) is used in order to derive the renormalized energy shift due to the gauge invariant K?llén-Sabry diagram of the two-photon vacuum polarization (VPVP) as well as the self energy vacuum polarization S(VP)E beyond the Uehling approximation. It is outlined, that no outer renormalization is required for the two-photon vacuum polarization and that only the inner renormalization has to be accomplished. It is shown that the so-called nongauge invariant spurious term is absent for a wide class of vacuum polarization (VP) diagrams if one applies the widely used spherical expansion of bound and free-electron propagator. This simplifies significantly calculations in bound state quantum electrodynamics. As one result of our paper the use of the BPHZ-approach in bound state QED is established. Received 28 September 2001     

感应电压叠加装置中角向传输线阻抗计算

在进行感应电压叠加装置设计时, 为了使初级脉冲形成与传输系统产生的快前沿高压脉冲均匀耦合到次级传输线, 需要建立感应腔的二维电路模型对电磁波在角向传输线中的传播过程进行分析, 并基于电路计算结果优化设计角向传输线阻抗分布规律,使次级传输线中电流能够均匀分布。由于角向传输线结构复杂, 没有精确求解阻抗值的解析公式, 介绍了一种基于电报方程和瞬态电磁场仿真求解复杂结构传输线阻抗值的方法, 采用该方法对等宽度和变化宽度两种结构角向传输线阻抗值进行了评估。研究结果表明,相比于三平板传输线阻抗计算公式, 采用微带传输线阻抗计算公式对角向传输线阻抗值进行求解结果更加精确。     

感应电压叠加装置中角向传输线阻抗计算

在进行感应电压叠加装置设计时, 为了使初级脉冲形成与传输系统产生的快前沿高压脉冲均匀耦合到次级传输线, 需要建立感应腔的二维电路模型对电磁波在角向传输线中的传播过程进行分析, 并基于电路计算结果优化设计角向传输线阻抗分布规律,使次级传输线中电流能够均匀分布。由于角向传输线结构复杂, 没有精确求解阻抗值的解析公式, 介绍了一种基于电报方程和瞬态电磁场仿真求解复杂结构传输线阻抗值的方法, 采用该方法对等宽度和变化宽度两种结构角向传输线阻抗值进行了评估。研究结果表明,相比于三平板传输线阻抗计算公式, 采用微带传输线阻抗计算公式对角向传输线阻抗值进行求解结果更加精确。