A theoretical investigation of the plasma klystron amplifier

Journal Article · Tue Jun 01 04:00:00 EDT 1993 · Physics of Fluids B; (United States)

DOI:https://doi.org/10.1063/1.860771· OSTI ID:6458756

Uhm, H S ^[1]

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1. Naval Surface Warfare Center, 10901 New Hampshire Ave., White Oak, Silver Spring, Maryland 20903-5640 (United States)

The plasma klystron amplifier concept is investigated. The plasma klystron consists of a relativistic annular electron beam propagating through a space between a plasma column and drift tube wall. The annular electron beam, premodulated at the first cavity in the klystron, enters the space. An axial electric field accompanied by the modulated beam excites space charge waves in the plasma column, which acts like an inductive medium amplifying the electrostatic waves. The physical mechanism of self-amplification of the electrostatic waves is the two-stream instability, which is investigated in detail. Instability criteria indicate that the plasma should be opaque to sustain instability. A theoretical model to describe current modulation of the annular electron beam propagating through the space is developed. The electron beam current is modulated by the amplifying electric field fed by the plasma column. Saturation distance of the current modulation is a weakly dependent function of the initial energy modulation at the first cavity. Thus, a relatively low-power microwave input may well excite the two-stream instability and deliver a highly modulated beam to the extraction cavity. Due to a relatively large growth rate of the instability, required interaction length of the beam and plasma column is short for most applications.

• OSTI ID: 6458756
• Journal Information: Physics of Fluids B; (United States), Journal Name: Physics of Fluids B; (United States) Vol. 5:6; ISSN PFBPEI; ISSN 0899-8221
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700340* -- Plasma Waves
Oscillations
& Instabilities-- (1992-)
AMPLIFIERS
BEAMS
COHERENT RADIATION
ELECTROMAGNETIC RADIATION
ELECTRON BEAMS
ELECTRON TUBES
ELECTRONIC EQUIPMENT
ENERGY RANGE
EQUIPMENT
INSTABILITY
KLYSTRONS
LEPTON BEAMS
MICROWAVE EQUIPMENT
MICROWAVE RADIATION
MICROWAVE TUBES
MODULATION
PARTICLE BEAMS
PLASMA INSTABILITY
PLASMA MICROINSTABILITIES
RADIATIONS
RELATIVISTIC RANGE
SPACE CHARGE
TWO-STREAM INSTABILITY