Acceleration and scattering of injected electrons in plasma beat wave accelerator experiments

Journal Article · Sun May 01 04:00:00 EDT 1994 · Physics of Plasmas; (United States)

DOI:https://doi.org/10.1063/1.870679· OSTI ID:5006812

Clayton, C E; Everett, M J; Lal, A; Gordon, D; Marsh, K A; Joshi, C ^[1]

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1. Department of Electrical Engineering, University of California at Los Angeles, Los Angeles, California 90024 (United States)

The results from experiments in which a two-frequency CO[sub 2] laser is used to beat-excite large-amplitude, relativistic electron plasma waves in a tunnel-ionized plasma are reported. The plasma wave is diagnosed by injecting a beam of 2 MeV electrons and observing the energy gain and loss of these electrons, as well as the scattering and deflection of the transmitted electrons near 2 MeV. Accelerated electrons up to 30 MeV have been observed. The lifetime of the accelerating structure as seen by small-angle Thomson scattering is about 100 ps, whereas the injected electrons are seen to be scattered or deflected by the plasma for several ns, with diffuse scattering occurring 0.5--1 ns after forming the plasma wave and whole beam deflection occurring at later times. A simple model, which includes laser focusing, ionization, transit time, and relativistic saturation effects, suggests that the wave coherence may be short lived while the wave fields themselves persist for a longer time. This may be the reason for the disparate time scales between the Thomson scattering and the electron scattering diagnostic. The whole beam deflection may be evidence for a Weibel-like instability at later times.

• DOE Contract Number: FG03-92ER40727
• OSTI ID: 5006812
• Journal Information: Physics of Plasmas; (United States), Journal Name: Physics of Plasmas; (United States) Vol. 1:5; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700350* -- Plasma Production
Heating
Current Drive
& Interactions-- (1992-)
ACCELERATION
BEAM INJECTION
BEAM-PLASMA SYSTEMS
BEAMS
CARBON DIOXIDE LASERS
ELECTROMAGNETIC RADIATION
ELECTRON BEAMS
ELEMENTS
GAS LASERS
HYDROGEN
INELASTIC SCATTERING
LASER RADIATION
LASERS
LEPTON BEAMS
NONMETALS
PARTICLE BEAMS
PLASMA ACCELERATION
RADIATIONS
RELATIVISTIC BEAM INJECTION
SCATTERING
THOMSON SCATTERING