Environmental Engineering Reference
In-Depth Information
dusty plasma is a convenient model for the analysis of both the formation and
destruction of ordered structures and various hydrodynamic effects.
We restricted ourselves to structures that dust particles form in gas discharge
plasma and give some examples of such structures. Then dust particles are inserted
in a plasma and are captured by electric traps in this plasma. Because the distance
between nearest neighbors of the structures formed is close to
l
, the radius of action
of an individual particle, the character of the preparation of the particle structure is
similar to filling a box with hard balls. Then it is necessary that the trap of the gas
discharge creates a vertical force for compensation of the gravitational force acting
on the particle. This may be realized in radio-frequency gas discharge where a sheet
is created between the electrodes and plasma with a voltage of approximately 10 V.
The electric field due to this voltage may prevent particles from falling down, and
this force compensates for the gravitational force acting on particles. Figure 6.13
shows examples of structures [107] formed in an electric trap of this discharge.
An electric trap of striations may be used for particle confinement, and Fig-
ure 6.14 demonstrates the particle structure [34] formed in glow discharge un-
der conditions of striation existence. Specific particle structures may be formed
in an inductively coupled discharge with an inductor of special construction [108].
Figure 6.13
Particle structures formed in the sheath of radio-frequency gas discharge near the
electrode [107].
