The amplification factor characterizing the amplification of acoustic disturbances in gas-discharge plasma is calculated with allowance for the nonuniform heating of neutral gas due to elastic collisions with the hot electron gas. It is shown that the heat release in the neutral plasma component due to elastic collisions between electrons and neutral particles is insufficient to provide the amplification factor of the order of measured values. It is also shown that the heat release due to superelastic collisions between excited atoms and atoms in the ground state can far exceed the heat release due to elastic collisions between electrons and neutral particles. A new mechanism of amplification of acoustic disturbances in plasma is proposed. This mechanism is associated with the superelastic relaxation of the nonequilibrium energy store accumulated in the atomic electron levels perturbed due to electron - atom inelastic collisions. It is shown that when the heat release is sufficiently high, one should assume that there exists a heat removal mechanism more efficient than heat conduction, this mechanism preventing intense gas heating, thereby providing acoustic wave amplification in plasma.
|Number of pages||8|
|Publication status||Published - Sep 1999|
ASJC Scopus subject areas
- Acoustics and Ultrasonics