What are some of the key characteristics of an electrically energised plasma discharge?

Some Main Characteristics of Electrical Energy Plasma Discharge

High Temperature Characteristics

During the plasma discharge process, extremely high temperatures are generated. When gas forms plasma under the action of electrical energy, the particles in the plasma (such as electrons and ions) possess high kinetic energy, and the intense collisions among these particles cause the temperature to rise sharply. For example, in an arc plasma, the temperature can easily reach several thousand degrees Celsius or even tens of thousands of degrees Celsius. This high temperature characteristic makes plasma discharge widely used in the field of material processing. For instance, in plasma cutting, it can quickly melt and cut metal materials, such as thick steel plates, and the cutting speed is much faster than that of traditional cutting methods, and the cutting surface is relatively neat.

High Energy Density

The plasma discharge region has the characteristic of high energy density. This is because electrical energy is concentratedly released into a relatively small spatial range in a short period of time, making the energy of the plasma in this region highly concentrated. Taking plasma spraying as an example, the high energy density plasma can heat the spraying materials (such as ceramic powders and metal powders) to a molten state and eject them at a high speed onto the surface of the workpiece to form a high-quality coating. This coating has good wear resistance, corrosion resistance and other properties and can be used for the surface protection of key components such as aero-engine blades.

Strong Oxidizing Property

The plasma contains a large number of active particles, such as oxygen ions and hydroxyl radicals, which are substances with strong oxidizing properties. In some plasma treatment processes, these active particles can react oxidatively with the organic substances and impurities on the surface of the treated materials. For example, in plasma cleaning, for some organic pollutants such as oil stains and photoresist on the surface of electronic components, the strongly oxidizing substances in the plasma can decompose them into small molecule substances such as carbon dioxide and water, thus achieving the purpose of surface cleaning. Moreover, this cleaning method is a dry cleaning and does not require the use of organic solvents, making it more environmentally friendly.

Luminescence Characteristics

The plasma discharge process will produce a luminescence phenomenon. This is because the electrons in the plasma will release photons during the transition process, and different gas components and discharge conditions will result in different colors and intensities of luminescence. For example, neon lights utilize the luminescence characteristics of plasma discharge. By filling different inert gases (such as neon gas and argon gas) into glass tubes and generating plasma discharge under high voltage, different colors of light are emitted, which are used for advertising, decoration and other purposes.

Good Conductivity

The plasma itself is a conductor, which is due to the existence of a large number of free electrons and ions in the plasma. In some special application scenarios, such as plasma stealth technology, the conductivity of the plasma is utilized to absorb and scatter radar waves, thereby reducing the probability of the target object being detected by radar. Meanwhile, in plasma display technology (such as plasma TV), the conductivity of the plasma also helps the electrons to be transmitted in the pixel units to realize the display of images.