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How does an electric field heat plasma through ohmic heating?

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How scientists use lasers to learn about the universe — plasma Learn about the PHELIX (Petawatt High-Energy Laser for Heavy Ion Experiments) laser at the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt, Germany. PHELIX is used for plasma and atomic physics research.

Ohmic heating, also known as Joule heating, is a process used to heat plasma by applying an electric field to the gas. This field accelerates and scatters free electrons, which then transfer energy to the plasma through collisions.1

This mechanism is fundamentally similar to how an electric oven heats its coils: as the electric current flows through the medium, the electrical resistance of the material converts electric energy into heat. Because electrons experience small energy losses during elastic collisions, they can be raised to significantly higher temperatures than other particles within the plasma.12

In laboratory settings, this electric field can be established using electrodes or through transformer action, where the field is induced by a changing magnetic field. The amount of heat generated is proportional to the electrical resistance and the square of the current, expressed by the formula $P = I^{2} R$ , where $P$ is the power loss in watts. Natural phenomena, such as lightning, also heat the atmosphere through this same ohmic process.12