Excitation of parasitic waves near cutoff in forward-wave amplifiers

Journal Article · Fri Oct 15 00:00:00 EDT 2010 · Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics (Print)

DOI:https://doi.org/10.1103/PHYSREVE.82.046404· OSTI ID:21464553

Nusinovich, Gregory S; Sinitsyn, Oleksandr V; Antonsen, Jr, Thomas M ^[1]

---

1. Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742-3511 (United States)

In this paper, excitation of parasitic waves near cutoff in forward-wave amplifiers is studied in a rather general form. This problem is important for developing high-power sources of coherent, phase controlled short-wavelength electromagnetic radiation because just the waves which can be excited near cutoff have low group velocities. Since the wave coupling to an electron beam is inversely proportional to the group velocity, these waves are the most dangerous parasitic waves preventing stable amplification of desired signal waves. Two effects are analyzed in the paper. The first one is the effect of signal wave parameters on the self-excitation conditions of such parasitic waves. The second effect is the role of the beam geometry on excitation of these parasitic waves in forward-wave amplifiers with spatially extended interaction space, such as sheet-beam devices. It is shown that a large-amplitude signal wave can greatly influence the self-excitation conditions of the parasitic waves which define stability of operation. Therefore the effect described is important for accurate designing of high-power amplifiers of electromagnetic waves.

• OSTI ID: 21464553
• Journal Information: Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics (Print), Vol. 82, Issue 4; Other Information: DOI: 10.1103/PhysRevE.82.046404; (c) 2010 The American Physical Society; ISSN 1539-3755
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMPLIFICATION
AMPLITUDES
COUPLING
ELECTROMAGNETIC RADIATION
ELECTRON BEAMS
EXCITATION
OPERATION
POWER AMPLIFIERS
STABILITY
VELOCITY
WAVELENGTHS
AMPLIFIERS
BEAMS
ELECTRONIC EQUIPMENT
ENERGY-LEVEL TRANSITIONS
EQUIPMENT
LEPTON BEAMS
PARTICLE BEAMS
RADIATIONS