Electron cyclotron resonance

Electron cyclotron resonance (ECR) is a phenomenon where electrons in a magnetic field absorb energy efficiently when exposed to electromagnetic radiation (like microwaves) at a specific frequency matching their circular gyration around magnetic field lines. When the microwave frequency equals the electrons' cyclotron frequency, they gain energy and spiral faster, which can be used to ionize gases or generate plasma. This principle is utilized in devices such as plasma sources, microwave heating, and particle accelerators, enabling precise control of electron energy and plasma properties for various industrial and scientific applications.