Dielectric barrier discharge

The gap distance between electrodes varies considerably, from less than 0.1 mm in plasma displays, several millimetres in ozone generators and up to several centimetres in CO2 lasers.

[9] A particular compact and economic DBD plasma generator can be built based on the principles of the piezoelectric direct discharge.

[15] [16] A multitude of random arcs form in operation gap exceeding 1.5 mm between the two electrodes during discharges in gases at the atmospheric pressure .

Such recombinations are directly proportional to the collisions between the molecules and in turn to the pressure of the gas, as explained by Paschen's Law.

A dielectric barrier discharge is one method of plasma treatment of textiles at atmospheric pressure and room temperature.

[20] An excimer lamp can be used as a powerful source of short-wavelength ultraviolet light, useful in chemical processes such as surface cleaning of semiconductor wafers.

An additional process when using chlorine gas for removal of bacteria and organic contaminates in drinking water supplies.

[22] Treatment of public swimming baths, aquariums and fish ponds involves the use of ultraviolet radiation produced when a dielectric mixture of xenon gas and glass are used.

[25][26] Dielectric barrier discharges were used to generate relatively large volume diffuse plasmas at atmospheric pressure and applied to inactivate bacteria in the mid 1990s.

In the field of biomedical application, three main approaches have emerged: direct therapy, surface modification, and plasma polymer deposition.

[28] Interest in plasma actuators as active flow control devices is growing rapidly due to their lack of mechanical parts, light weight and high response frequency.

Drivers for this type of electric load are power HF-generators that in many cases contain a transformer for high voltage generation.

Differently, drivers for pulsed operation suffer from rather low power factor and in many cases must fully recover the DBD's energy.

DBD plasma actuators employed for airflow control applications. [ 1 ]
Typical construction of a DBD device wherein one of the two electrodes is covered with a dielectric barrier material. The lines between the dielectric and the electrode are representative of the discharge filaments, which are normally visible to the naked eye.
A dielectric barrier discharge produced using mica sheets as dielectric , put on two steel plates as electrode. The discharge is taking place in normal atmospheric air, at about 30 kHz, with a discharge gap of about 4 mm. The foot of the discharge is the charge accumulation on the barrier surface.
Dielectric barrier discharges can also be constructed in a concentric fashion: The high voltage electrode is the outer ring, the ground in the inner capillary, and they are separated by a glass capillary. This format can be useful for flowing a gas through the discharge continuously, for example as an ionisation source in mass spectrometry.