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Propagation of sound in glow discharge plasma
Vladimir Soukhomlinov, Nikolay Gerasimov and Valery A Sheverev

Vladimir Soukhomlinov1, Nikolay Gerasimov1 and Valery A Sheverev2
1 Research Institute for Physics, Saint-Petersburg State University, Saint-Petersburg, Russia
2 Polytechnic University, Six Metrotech Center, Brooklyn, NY 11201, USA
Abstract. Propagation of sound in a medium where the rate of local heat addition is a function of gas density is analysed theoretically and the results are applied for modelling the experimentally observed effect of amplification of acoustic waves by an extended glow discharge in air. The model adequately describes the experimental dependences of the gain on the wave frequency and discharge power density and predicts that the amplification of sound by an unconfined glow discharge in air increases with discharge current density but does not change noticeably with gas pressure when the current density is kept constant. Quantitative estimates indicate that a gain of as high as 1 m-1 (or 9 dB for a 60 dB wave passing through 1 m of plasma) could be realized using a discharge in air with a current density of 100 mA cm-2.
Print publication: Issue 8 (21 April 2007)
Received 6 November 2006
Published 4 April 2007




Reflection of sound by glow discharge plasma
Vladimir Soukhomlinov, Valery A Sheverev and Calin Tarau



Sound amplification in inhomogeneous flows of nonequilibrium gas
http://www.springerlink.com/content/f88l21pvhl6pv771/


Hypersound amplification by a superlattice in a nonquantised electric field
G M Shmelev et al 1988 J. Phys. C: Solid State Phys. 21 L1073-L1077 doi:10.1088/0022-3719/21/33/001
G M Shmelev, S Y Mensah and G I Tsurkan
V I Lenin State Univ., Kishinev, USSR
Abstract. Short-wave sound absorption propagating along the axis of a semiconductor superlattice by electrons of the lowest miniband in a nonquantised electric field is investigated theoretically. The mechanism of the attenuation of phonons is due to Landau damping. The relationship discovered for the absorption coefficient Gamma = Gamma (E) is essentially different from that for homogeneous materials, and, additionally the threshold field at which the absorption switches over to amplification depends on the superlattice parameters and the length of the sound wave. The more important difference between short-wave sound amplification by a superlattice and amplification in the homogeneous materials is the possibility of finding a field E* such that - Gamma (E*)>or= Gamma (-E*). This situation allows in principle the use of a superlattice as a hypersound generator similar to a generator of long-wave sound. The above generator is impossible to construct in the case of homogeneous semiconductors.
Print publication: Issue 33 (30 November 1988)