Thomson scattering of an electromagnetic wave in a plasma density irregularity is considered. A new effect is found that the scattered waves generation and superposition near the electron density extremum may result in a substantial modulation of the scattered signal frequency spectrum. Due to this effect, the observable spectrum shape will be substantially different from that for the electron density fluctuations. This fact should be taken into account when interpreting Thomson scattering experiments.
3. Fejer, J. A., "Radio-wave scattering by an ionized gas in thermal equilibrium," J. Geophys. Res., Vol. 65, No. 9, 2635-2636, 1960.
3. Hagfors, T., "Density fluctuations in a plasma in a magnetic field, with applications to the ionosphere," J. Geophys. Res., Vol. 66, No. 6, 1699-1712, 1961.
4., Evans and J. V., "Theory and practice of ionosphere study by Thomson Scatter radar," Proc. IEEE, Vol. 57, No. 4, 496-530, 1969.
5. Farley, D. T., Incoherent scatter radar probing, Modern Ionospheric Science, Copernicus Society, Katlenburg-Lindau, Germany, 1996.
6. Beynon, W. J. G. and P. J. S. Williams, "Incoherent scatter of radio waves from the ionosphere," Rep. Prog. Phys., Vol. 41, No. 6, 909-956, 1978.
7. Akhiezer, A., et al., Plasma Electrodynamics, Pergamon, Oxford-New York, 1975.
8. Hagfors, T., "Incoherent scattering radar observations of the plasma line with a chirped pulse system," Radio Sci., Vol. 17, No. 3, 727-734, 1982.
9. Isham, B. and T. Hagfors, "Observations of the temporal and spatial development of induced and natural plasma lines during HF modification experiments at Arecibo using chirped ISR," J. Geophys. Res., Vol. 98, No. A8, 13605-13625, 1993.
10. Mishin, E. and T. Hagfors, "On origin of outshifted plasma lines during HF modification experiments," J. Geophys. Res., Vol. 102, No. A12, 27265-27269, 1997.
11. Krasnoselskikh, V. V., T. Dudok deWit, and S. D. Bale, "Determining the wavelength of Langmuir wave packets at the Earth’s bow shock," Ann. Geophys., Vol. 29, No. 3, 613-617, 2011.
12. Isham, B., et al., "Cavitating langmuir turbulence in the terrestrial aurora," Phys. Rev. Lett., Vol. 108, No. 10, 105003, 2012.
13. Puchkov, V. A., "Longitudinal fluctuations in a nonuniform collisional plasma with nonequilibrium particle distributions," Plasma Phys. Rep., Vol. 35, No. 3, 234-243, 2009.
14. Klimontovich, Yu. L., The Statistical Theory of Non-equilibrium Processes in a Plasma, Pergamon, Oxford-New York, 1967.
15. Ginzburg, V. L., The Propagation of Electromagnetic Waves in Plasmas, Pergamon, Oxford-New York, 1970.
16. Abramowitz, M. and I. Stegun, Handbook of Mathematical Functions, National Bureau of Standards, Washington, DC, 1964.
17. Puchkov, V. A., "Theory of fluctuations in a nonequilibrium plasma with allowance for collisions between plasma particles," Plasma Phys. Rep., Vol. 24, No. 5, 436-449, 1998.
18. Puchkov, V. A., "Electrostatic fluctuations in nonequilibrium plasmas with particle collisions," Phys. Lett. A, Vol. 372, No. 42, 6400-6403, 2008.