Analysis of the deflection system for a magnetic-field-immersed magnicon amplifier

Hafizi, B.; Seo, Young-Jin; Gold, Steven H.; Manheimer, W. M.; Sprangle, P.

doi:10.1109/27.142824

Cited by 24 publications

(5 citation statements)

References 6 publications

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“…To assess the effects of beam loading it is necessary to solve the wave equation with the source term evaluated with the aid of the orbit in (5). Following [7], the current density for a monoenergetic beam of electrons with energy may be written as where is the beam current, is the orbit in theplane, expressed as a function of the time and the entry time into the cavity, and is the electron distribution-which is a function of the initial coordinates and momenta -subject to the normalization condition It is thus necessary to solve the wave equation with the orbit given by (5) inserted into the expression for the current density. The solution of the wave equation can be readily obtained by substituting a vector potential of the form given in (1) into the left-hand side.…”

Section: Dispersion Relationmentioning

confidence: 99%

“…For the right-hand side use is made of the orbit in (5) to evaluate the current density . Since this calculation is standard [4], [7], for brevity, we quote the result from [7]. For an azimuthally symmetric distribution function and in the paraxial approximation the ratio of the electric field in the gain cavity to that in the drive cavity is given by (6) where Here, , is the length of the cavity, , is the Alfvén current,…”

Section: Dispersion Relationmentioning

confidence: 99%

“…The theoretical work at NRL has concentrated on understanding the physics issues involved in the magnicon amplifier [4], [7]- [11]. In an early study a detailed linear analysis of the deflection system was presented.…”

Section: Introductionmentioning

confidence: 99%

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Beam loading in magnicon deflection cavities

Hafizi

Gold

1997

IEEE Trans. Plasma Sci.

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Analysis of the beam-deflection cavity interaction in a magnicon is presented and compared with experiment. For a driven cavity a dispersion relation is obtained wherein the interaction modifies the cold-cavity quality factor and the resonance frequency. In terms of a lumped-parameter equivalent circuit the interaction corresponds to a complex-valued beam admittance Y b in parallel with the cavity admittance. The response of the gain cavities is modified by the same admittance. In a magnicon, Y b is a sensitive function of the solenoidal focusing magnetic field B 0 , thus providing a convenient means of adjusting the cavity properties in experiments. When the relativistic gyrofrequency is twice the drive frequency, Im Y b = 0 and the beam does not load the cavity. Analytical expressions of the variation of the detuning, instantaneous bandwidth (i.e., loaded quality factor) and gain with B0 are derived. Simulation results are presented to verify the linear analysis with ideal beams and to illustrate the modifications due to finite beam emittance. Results of the magnicon experiment at the Naval Research Laboratory are examined in the light of the analysis.

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Section: Dispersion Relationmentioning

confidence: 99%

Section: Dispersion Relationmentioning

confidence: 99%

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Beam loading in magnicon deflection cavities

Hafizi

Gold

1997

IEEE Trans. Plasma Sci.

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“…Shortduration pulses are used for microwave generation in klystrons and related devices. Several groups [1][2][3][4][5][6][7] have been working on microwave generation, especially in view of the requirements of future TeV linear colliders. A major research and development activity is being conducted at FMT, and robust micropulse electron guns (MPG) have been developed [8,9] to produce selfbunched, high-current-density beams.…”

Section: Introductionmentioning

confidence: 99%

High-current micro-pulse electron guns and accelerator applications

Guharay

Len

Mako

PACS2001. Proceedings of the 2001 Particle Accelerator Conference (Cat. No.01CH37268)

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A major research activity is being pursued at FMT to develop high-current, short-duration pulses of electron beams for injectors in electron accelerators as well as for microwave generation in klystrons and related devices. Design and development of gun cavities, in the frequency range of 1 to 12 GHz, are conducted through a comprehensive task including simulation, analytical and experimental studies. With the goal to build high-power, high-frequency klystrons, one of our most recent efforts is focused on developing an X-band cavity at about 9 GHz for generating high-current, bunched micropulses of electron beams. The full system has been designed and built, and it is running reliably. An average beam current density > 20A/cm 2 over a macropulse, or 400 A/cm 2 over a micropulse, has been measured for a modest input rfpower, ~60 kW, into the gun cavity. In addition, experiments are being conducted to develop an electron gun at 1.3 GHz, with gating capabilities, and match beam requirements for Argonne Wakefield Accelerator.

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“…Magnicons operating at high voltages and at many GHz are being developed both in the U.S. [3] and in Russia, primarily as the RF source for the Next Linear Collider. However, the experimental evidence to date [4] indicates that the electron dynamics in the magnicon are complicated, and it has been difficult to verify the predictions of magnicon computer models.…”

Section: Introductionmentioning

confidence: 99%

Rigid-beam model of a high-efficiency magnicon

Rees

Tallerico

Humphries

Proceedings of International Conference on Particle Accelerators

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The magnicon is a new type of high-efficiency deflection-modulated amplifier developed at the Institute of Nuclear Physics in Novosibirsk, Russia. The prototype pulsed magnicon achieved an output power of 2.4 MW and an efficiency of 73% at 915 MHz. This paper presents the results of a rigid-beam model for a 7OOMHz, 2.5MW 82%efficient magnicon. The rigid-beam model allows for characterization of the beam dynamics by tracking only a single electron. The magnicon design presented consists of a drive cavity; passive cavities; a pi-mode, coupled-deflection cavity; and an output cavity. It represents an optimized design. The model is fully self-consistent, and this paper will present the details of the model and calculated performance of a 2.5~MW magnicon.

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Analysis of the deflection system for a magnetic-field-immersed magnicon amplifier

Cited by 24 publications

References 6 publications

Beam loading in magnicon deflection cavities

Beam loading in magnicon deflection cavities

High-current micro-pulse electron guns and accelerator applications

Rigid-beam model of a high-efficiency magnicon

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