Thomson Scattering Measurements of the Langmuir Wave Spectra Resulting from Stimulated Raman Scattering

Thomson scattering was used to measure the Langmuir wave spectrum generated by stimulated Raman scattering. This experiment detected Langmuir waves with components both parallel and antiparallel to the incident laser's wave vector ${\overrightarrow{k}}_0$. The parallel component was attributed to stimulated Raman scattering. However, the Langmuir waves moving antiparallel to ${\overrightarrow{k}}_0$, which cannot be explained by stimulated Raman scattering, were attributed to the Langmuir decay instability.