Britannica
Sources used in this answer
How does a gas become ionized into plasma?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
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.
A gas becomes ionized into plasma when its atoms or molecules gain or lose electrons, converting them into electrically charged ions. This process typically occurs through the following mechanisms:1
- Thermal Ionization: Heating a gas to extremely high temperatures causes vigorous collisions between atoms and molecules, stripping electrons away. While some substances with low ionization energy can ionize at lower temperatures, most gases require temperatures in the range of 10,000 K to achieve significant ionization.23
- Electrical Discharge: Applying a strong electric field to a gas accelerates free electrons, which then collide with neutral gas molecules and knock off additional electrons. This ohmic heating is used in laboratory settings and occurs naturally in phenomena like lightning.13
- Photoionization: In space and the upper atmosphere, photons from ultraviolet radiation or X rays are absorbed by gas atoms, providing enough energy to eject electrons.123
- Particle Impact: Energetic charged particles, such as those found in auroras, can collide with gas atoms to cause ionization.13