sähköpurkaantumista

Sähköpurkaantuminen, often translated as electrical discharge, refers to the passage of electric current through a medium that is normally an electrical insulator, such as air or a vacuum. This phenomenon occurs when the electric field strength across the insulator exceeds a critical value, known as the dielectric strength. At this point, the insulator can no longer maintain its resistive properties, and a conducting path is formed.

There are several forms of electrical discharge. A common example is a spark, which is a brief, sudden discharge that can be observed visually. Lightning is a large-scale example of a spark discharge occurring naturally in the atmosphere. Another form is an arc discharge, characterized by a continuous and luminous electrical discharge between two electrodes. Arc welding utilizes this principle. Corona discharge is a less intense discharge that occurs at sharp points or edges of conductors when the electric field is concentrated. This can sometimes be seen as a faint glow. Glow discharge is a type of electrical discharge that occurs at lower pressures and is characterized by a relatively uniform glow filling a discharge tube.

The process of electrical discharge involves the ionization of the gas or medium. In many cases, free electrons gain enough kinetic energy from the electric field to collide with neutral atoms or molecules, knocking off other electrons and creating more ions and free electrons. This cascade effect leads to an avalanche of charge carriers, forming a conductive channel through which current can flow. The energy released during a discharge can manifest as light, heat, and sound. Electrical discharges have numerous applications, including lighting, plasma generation, and electrostatic precipitators for air purification.