Theory of a ubitron in a corrugated waveguide

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:435469

Freund, H P; Nguyen, K; Pershing, D E ^[1]

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1. Naval Research Lab., Washington, DC (United States)

A K{sub a} band ubitron amplifier is currently under development at NRL utilizing grazing intersection for wide instantaneous bandwidth, circularly polarized wiggler and microwave fields for high gain and power, and a high quality Pierce gun generating a cylindrical, uniform density electron beam for high efficiency. The dispersion characteristics of a periodic waveguide can be exploited for low voltage ubitron operation. Operation in the HE{sub 11} mode of a corrugated cylindrical waveguide permits broader bandwidth amplification at lower voltages than is possible with a smooth waveguide. While the wave is slower than the smooth waveguide dispersion characteristic, the amplifier still operates on the fundamental space harmonic as a fast-wave device. An extensive investigation of several waveguide/wiggler geometries has been completed. Preliminary calculations using a dielectrically loaded corrugated waveguide indicate that 20% bandwidth operation in K{sub a} band is possible at voltages {approximately} 150 kV with a 8--9 mm period wiggler generating a 930 G transverse magnetic field. Design details and performance calculations using the 3-D nonlinear code TARANTULA will be presented.

• Sponsoring Organization: Office of Naval Research, Washington, DC (United States)
• OSTI ID: 435469
• Report Number(s): CONF-960634--
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
COMPUTERIZED SIMULATION
DESIGN
MICROWAVE AMPLIFIERS
NAVAL RESEARCH LABORATORY
OPERATION
OSCILLATION MODES
PERFORMANCE
WAVEGUIDES