Equations are derived describing the large-signal operation of traveling-wave amplifier, including effects ac space charge and attenuation along helical slow-wave structure. The equations constitute a system nonlinear partial-differential-integral valid with reasonable approximations for all values parameters which encountered in typical high-power amplifiers. appear relative injection velocity b, gain parameter C, space-charge K B, loss d, input-signal level A <inf...

A reaction-rate analysis is used to determine the relative importance of predominant ionization and loss mechanisms in a neon low-voltage arc. Experimental data are derived from various experiments density, cross section, etc. It found that resonance metastable state atoms primarily generated region near cathode which corresponds ``cathode ball-of-fire'' The ion-generation process be result collisions between excited cause formation molecular ion. Direct ground-state secondary but...

A number of experimental techniques have been combined to study radiation-induced defects that are complementary $F$ centers. One series experiments, in which the resistance dislocation motion due interstitial centers was monitored by means flow-stress changes, indicated produced irradiation at 80\ifmmode^\circ\else\textdegree\fi{}K and warming dark room temperature were less effective barriers than those above 150\ifmmode^\circ\else\textdegree\fi{}K. In a second measurement vacancy-center...

The microwave circuit characteristics of bulk GaAs transit-time mode and limited space-charge accumulation (LSA) oscillators have been evaluated experimentally theoretically. Experimental measurements were performed with a waveguide-coaxial having two experimental degrees freedom in which the radiation impedance at device contacts was by dyadic Green's function method. Experiments conducted three rectangular waveguide circuits fixed bias voltage established that LSA frequency tuning range is...

The phenomenon of phase focusing in linear-beam devices is investigated theoretically by modifying the nonlinear interaction equations for such as traveling-wave amplifier (TWA) to accommodate spatially-varying parameters and then investigating their use under a variety operating conditions. Phase can be accomplished either tapering RF circuit velocity or applying dc voltage gradient along beam structure. Both approximate analytical solutions general computer are presented each...

As a result of the inherent nonlinearity beam-circuit wave interaction process in high-power microwave amplifiers, there are harmonics generated when one signal is applied to input and both intermodulation products multiple component signals applied. The effect these reduce available power levels fundamental signals. In this investigation signals, noise, combinations considered as inputs traveling-wave crossed-field amplifiers. A one-dimensional nonlinear theory developed consider...

The low-to-moderate RF conversion efficiencies characteristic of kinetic energy devices may be enhanced by appropriately tapering the circuit phase velocity. nonlinear interaction equations have been solved in closed form for an HKB (hard-kernel-bunch) model to obtain optimum taper form. Several velocity forms investigated experimental amplifiers and power output, gain, efficiency, shift characteristics these are discussed detail. Conversion up 50 percent near constant output a 20-dB...

The equivalence of the differential-equation and integral-equation approaches to solution nonlinear traveling-wave amplifier problem is shown rigorously. equations can be transformed one into other without making any additional assumptions. space-charge expression developed on basis considering electron distribution in phase space give same form for weighting function as a based space. Efficiency calculations are compared two methods agreement excellent. Corrections earlier included. effect...

Abstract Previously all analyses of linear stream devices assumed that the electron was unbundled before interacting with an r.f. wave on a propagating circuit. Linear and non-linear are presented for prebunched beams travelling in both growing-wave beating-wave devices. In case modulation is sinusoidal described terms space-charge waves. The increase gain achieved calculated conditions optimizing respect to predrift angle initial phase developed analytically. Calculations analysed TWA...

In computing noise transport by the Monte Carlo technique, electrons, their two velocity components and emission times, are generated in a random manner. The electron equations of motion integrated numerically to determine subsequent position coordinates electrons. first phase computer program initial conditions specified order fill diode. second electrons drift according self-consistent space-charge fields. Under steady-state data for number recorded several sections beam unit time...

Abstract Introduction On-site milling with mobile machine tools is a popular solution for the modification of large or immobile metal parts. For such operations transportation and setup constitutes delicate process. Hence, designs must find good compromise between power, structural rigidity, adaptability. However, this can lead to flexible structures which are susceptible chatter. Materials methods The present article dedicated chatter identification in numerically controlled using...

An experimental investigation of the low-voltage arc mode hot-cathode discharge has been carried out in a diode utilizing planar electrode geometry. The consisted predominantly Langmuir-probe measurements neon atmosphere. Measurements were also obtained argon, xenon, and hydrogen hydrogen-neon argon-neon mixtures. probes planar, guard-ringed volt-ampere characteristic Torr range gas pressure was investigated to further define arc. For ample electron emission at cathode there are two stable...

A relativistically correct large-signal theory is developed for the analysis of high-power, axially symmetric traveling-wave amplifiers in order to investigate physical phenomena involved interaction process. The nonlinear integro-differential system equations are from Lorentz force equation, one-dimensional equivalent circuit wave and continuity charge relation. These applied two electron stream models: a ring model which permits effects nonlaminar flow space-charge forces be evaluated,...

Low-field 10-GHz noise radiation and attendant rf current oscillations are generated in 10-mm-long specimens of n-type InSb at 77°K. Using a special experimental arrangement, both the azimuthal polar orientation applied magnetic field can be varied spatial distribution along length specimen also measured. Two distinct modes low-field found specimens. One mode (B∥ mode) prevails when is aligned parallel to direction flow other transverse flow. The B⊥ investigated considerable detail it...

A new analog device, called a Poisson cell, has been developed which aids in obtaining solutions to either Laplace's equation or Poisson's equation. The cell may be used simulate such potentials as electric potential, magnetic gravitational and the velocity potential of irrotational flow; it applications fields hydrodynamics, heat conduction, aerodynamics. is solid volume-conducting medium made from homogeneous mixture hydrostone graphite. Electrode configurations painted on surface with...

The noise transport phenomena in a two-dimensional diode operated under space-charge-limited conditions are investigated by means of the statistical Monte Carlo method. Effects on characteristics an electron beam multi-dimensional nature potential distribution vicinity minimum evaluated. Contrary to both single velocity and multivelocity linear small-signal theories, parameters <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</tex> , II, -- II...

A half-Maxwellian <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</tex> -component velocity distribution and a full-Maxwellian xmlns:xlink="http://www.w3.org/1999/xlink">z</tex> are assumed in order to evaluate the position depth, y <inf xmlns:xlink="http://www.w3.org/1999/xlink">m</inf> V , of potential minimum as boundary-value problem. The various dc parameters such voltage distribution, space-charge density, current density components...

An X-band ruby traveling-wave maser (TWM) has been constructed and tested in which the RF structure is a double-ridge ladder line signal coupled into out of with coaxial lines. The pump power propagated waveguide mode device operated at below liquid helium temperatures. A four-inch electromagnet was used. TWM push-pull point frequency 24 Gc approximately 9.65 Gc; magnetic field 4.1 kilogauss. Electronic gains 15 db have obtained bandwidths as high 130 Mc were observed. Reduced losses longer...

The starting conditions for the O-type backward-wave oscillator are computed large values of C, QC and d, using both digital analog methods. A general method solving complex polynomials called "downhill" is applied to secular equation then RF voltage obtain conditions. computer used solve simultaneously, by trial error method, linear circuit ballistic differential equations. modulated BWO in order determine effects modulations on Extensive calculations have been made a wide range d.

In large-diameter electron stream traveling-wave amplifiers there is a significant variation of the circuit electric field across stream. Most analyses neglect effects these variations. An approximate method has been used to study effect transverse variations on gain and effciency large-signal amplifiers. The annular subdivided into number rings each containing an equal fraction total current. It assumed that varies over cross section segment different coupling circuit. space-charge...

A transmission-line analog is developed for crossed-field space-charge flows from the simultaneous solution of Maxwell's equations, Lorentz force equation, and continuity equation. thin one-dimensional injected beam assumed. The resulting fifth-degree secular equation solved several values ωc/ωp. five system waves consist a pair hybrid waves, near-cyclotron near-synchronous wave. results indicate that noise transformers may be based on an equivalent piecewise uniform transmission line.

The effects of nonuniformities in the circuit phase velocity and beam potential on start-oscillation conditions an O-type backward-wave oscillator (BWO) are investigated. include linear, quadratic, exponential tapers gradients. It is shown that for weak or voltage gradients current may be lower than a uniform tube; however, when taper gradient made stronger particular value which depends operating parameters, no-oscillation region results. latter result indicates such utilized to suppress...

The amplification or generation of coherent signals by electron-beam—plasma interactions requires the creation a high-density stable plasma. A plasma density approximately 1015 particles/cm3 is required to produce resonance frequency 300 Gc/sec. in an arc-discharge has been increased using mechanical and magnetic constriction methods with result that np=7.5×1014 realized at discharge current 4 argon. Double Langmuir probe measurements on temperature are presented interpreted for zero finite...