Dispersion analysis of symmetric transverse magnetic modes in a split cavity oscillator

Journal Article · Sun Nov 01 04:00:00 EST 1992 · Journal of Applied Physics; (United States)

DOI:https://doi.org/10.1063/1.352209· OSTI ID:7010700

Lemke, R W ^[1]

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1. Sandia National Laboratories, P. O. Box 5800, Albuquerque, New Mexico 87185 (United States)

The split cavity oscillator (SCO) is a resonant cavity device which can be used to modulate the current of a relativistic electron beam. The modulated electron beam can be used to produce high-power microwaves. The SCO consists of a cylindrical cavity resonator which has been divided (split) into two identical regions (cavities) by a thin conducting foil (or screen) whose radius is less than the inner radius of the cylinder. The resulting gap between the foil perimeter and inner cylinder wall forms an annular slot which couples the cavities electromagnetically. The SCO supports standard transverse magnetic (TM) modes, in addition to split cavity TM modes. The latter will interact unstably with an electron beam, thereby producing a high degree of current modulation in a short distance. For the purpose of characterizing split cavity TM modes, and developing a design tool for SCOs, a cold dispersion relation (no electron beam) is derived by solving Maxwell's equations for the fields in an equivalent periodic structure. The dispersion relation and field solutions are employed to numerically calculate eigenfrequencies and eigenfunctions for the SCO. The latter are used to develop predictive formula for the SCO oscillation frequency, and to gain some understanding of the interaction that takes place when an electron beam is present.

• OSTI ID: 7010700
• Journal Information: Journal of Applied Physics; (United States), Journal Name: Journal of Applied Physics; (United States) Vol. 72:9; ISSN 0021-8979; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
426000* -- Engineering-- Components
Electron Devices & Circuits-- (1990-)
BEAMS
CAVITY RESONATORS
DIFFERENTIAL EQUATIONS
DISPERSION RELATIONS
ELECTROMAGNETIC RADIATION
ELECTRON BEAMS
ELECTRONIC EQUIPMENT
ENERGY RANGE
EQUATIONS
EQUIPMENT
LEPTON BEAMS
MAGNETIC FIELDS
MAXWELL EQUATIONS
MICROWAVE RADIATION
MODULATION
PARTIAL DIFFERENTIAL EQUATIONS
PARTICLE BEAMS
PRODUCTION
RADIATIONS
RELATIVISTIC RANGE
RESONATORS