Autoresonant beat-wave generation

Journal Article · Fri Dec 15 04:00:00 EST 2006 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.2390692· OSTI ID:20860455

Lindberg, R R; Charman, A E; Wurtele, J S; Friedland, L; Shadwick, B A ^[1]

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1. University of California, Berkeley Department of Physics, Berkeley, California 94720 and Lawrence Berkeley National Laboratory Center for Beam Physics, Berkeley, California (United States)

Autoresonance offers an efficient and robust means for the ponderomotive excitation of nonlinear Langmuir waves by phase-locking of the plasma wave to the slowly chirped beat frequency of the driving lasers via adiabatic passage through resonance. This mechanism is analyzed for the case of a cold, relativistic, underdense electron plasma, and its suitability for particle acceleration is discussed. Compared to traditional approaches, this new autoresonant scheme achieves larger accelerating electric fields for given laser intensity; the plasma wave excitation is much more robust to variations in plasma density; it is largely insensitive to the precise choice of chirp rate, provided only that it is sufficiently slow; and the suitability of the resulting plasma wave for accelerator applications is, in some respects, superior. As in previous schemes, modulational instabilities of the ionic background ultimately limit the useful interaction time, but nevertheless peak electric fields approaching the wave-breaking limit seem readily attainable. The total frequency shift required is only of the order of a few percent of the laser carrier frequency, and might be implemented with relatively little additional modification to existing systems based on chirped pulse amplification techniques, or, with somewhat greater technological effort, using a CO{sub 2} or other gas laser system.

• OSTI ID: 20860455
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 12 Vol. 13; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ACCELERATION
ACCELERATORS
ELECTRIC FIELDS
ELECTRONS
EXCITATION
GAS LASERS
LIGHT TRANSMISSION
NONLINEAR PROBLEMS
PLASMA DENSITY
PLASMA GUNS
PLASMA INSTABILITY
PLASMA WAVES
PONDEROMOTIVE FORCE
PULSES
RELATIVISTIC PLASMA
RELATIVISTIC RANGE
RESONANCE
VARIATIONS