free-electron laser

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A type of laser that works by the stimulated emission of electromagnetic radiation produced by the motion of electrons moving rapidly in external magnetic fields. A beam of electrons at relativistic speed is produced in an accelerator and passed into a region in which the electrons are forced to follow a sinusoidal path by an array of magnets (the ‘undulator’). The associated synchrotron radiation is highly coherent as in a conventional laser. Free-electron lasers can be tuned to a narrow frequency range and radiation can be produced over a wide range, from microwaves to soft X-rays. The free-electron-laser mechanism might account for some aspects of pulsar radiation.

Subjects: Physics.

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