A class of radiation mechanisms in which a charged particle (usually an electron) follows a spiral path in a magnetic field and thereby radiates energy in the form of electromagnetic waves. The name means ‘magnetic braking radiation’. If the velocity of the particle is much less than the speed of light, the emission is known as cyclotron radiation. If the particle’s speed is an appreciable fraction of the speed of light the emission is known as gyrosynchrotron radiation, and for speeds very close to that of light it is termed synchrotron radiation. In some usages, magnetobremsstrahlung is regarded as synonymous with synchrotron radiation.