Streamer positive

Kulikovsky, A.A. (1997) Production of chemically active species in the air by a single positive streamer in a nonuniform field, IEEE Trans. PI. Sci. 25, 439-46. 

Naidis, G.V. (1996) On streamer interaction in a pulsed positive corona discharge, J. Phys. D Appl. Phys. 29, 779-83. 

The load is a coaxial combustion chamber. The center corona electrode is positive, and the chamber wall is at ground potential. Previous experiments indicate that the corona discharge impedance is approximately 250 Ohm, sharply dropping to < 100 Ohm when streamers reach the opposite electrode and an arc forms [3, 4]. 

A strong primary avalanche is able to amplify the external electric field and form a streamer. When the streamer chaimel cotmects the electrodes, the current may be significantly increased to form the spark. The avalanche-to-streamer transformation takes place when the internal field of an avalanche becomes comparable with the external one. If the gap is short, the transformation occurs only when the avalanche reaches the anode. Such a streamer that grows from anode to cathode and called the cathode-directed or positive streamer. If the gap and overvoltage are large, the avalanche-to-streamer transformation can take place far from the anode, and the anode-directed or negative streamer grows toward both electrodes. 

Figure 4-6. Illustration of the cathode-directed (positive) streamer (a) propagation of the positive streamer (b) electric field near the streamer head.

Figure 4-8. Illustration of streamer propagation from a positive 2-em-diameter rod to a plane loeated at a dis-tanee of 1.5 m applied voltage 125 kV Equipotential surfaces are shown as fraetions of the total applied voltage.

Figure 4-10. Illustration of interaction between the DBD mierodiseharges (quasi-repulsion) related to an eleetrie field distortion eaused by the microdiseharge remnant. Streamer formation (left-hand side) and plasma ehannel (and mierodiseharge remnant) eleetrie field distortion (right-hand side) are due to space eharges. The figure shows the eleetrie field from the mierodiseharge, the applied external eleetrie field, and their superposition. In the presence of a spaee positive eharge, the eleetrie field is increased at the cathode and decreased at the anode.

Thus, the interaction of streamers in DBD can lead to the formation of an organized structure of microdischarges (similar to Coulomb crystals see Fridman Kennedy, 2004), which plays a significant (sometimes positive, sometimes negative) role in plasma-chemical applications. From this perspective it is important to analyze how highly organized the... 

For nonuniform fields, a is a function of the position between the electrodes, and the breakdown voltage can be calculated from the so-called streamer criterion. 

For a given liquid, positive streamers (originating from the anode) are always faster than the negative ... 

Fig. 4. Shock waves from positive streamers in Marcol 70. Streamer is supersonic at 106 kV (1.8 km/s) and subsonic at 63 kV (1.07 km/s) sound velocity 1.4 km/s (Devins et al., 1981)...

Fig. 5. Illustrating the decay of a positive streamer in a string of bubbles (Chadband, 1980).

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