Observation of the saturation of Langmuir waves driven by ponderomotive force in a large scale plasma

Technical Report · Sun Jun 22 04:00:00 EDT 1997

DOI:https://doi.org/10.2172/562472· OSTI ID:562472

Kirkwood, R. K.; Moody, J. D.; MacGowan, B. J.; Glenzer, S. H.; Kruer, W. L.; Estabrook, K. G.; Wharton, K. B.; Williams, E. A.; Berger, R. L. ^[1]

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1. University of California, Lawrence Livermore National Lab., CA (United States)

We report the observation of amplification of a probe laser beam (I {le} 1 {times} 10{sup 14} W/cm{sup 2}) in a large scale ({approximately} 1 mm) plasma by interaction with a pumping laser beam (I = 2 {times} 10{sup 15} W/cm{sup 2}) and a stimulated Langmuir wave. When the plasma density is adjusted to allow the Langmuir wave dispersion to match the difference frequency and wave number of the two beams, amplification factors as high as {times} 2.5 result. Interpretation of this amplification as scattering of pump beam energy by the Langmuir wave that is produced by the ponderomotive force of the two beams, allows the dependence of Langmuir wave amplitude on ponderomotive force to be measured. It is found that the Langmuir wave amplitude saturates at a level that depends on ion wave damping, and is generally consistent with secondary ion wave instabilities limiting its growth. 20 refs., 4 figs.

• Research Organization: Lawrence Livermore National Lab., CA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 562472
• Report Number(s): UCRL-ID--128007; ON: DE98051047
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
AMPLIFICATION
DAMPING
DECAY INSTABILITY
ELECTROMAGNETIC RADIATION
ELECTRON PLASMA WAVES
EXPERIMENTAL DATA
ION ACOUSTIC WAVES
PLASMA
PONDEROMOTIVE FORCE
RAMAN EFFECT
SATURATION