ABSTRACT
As shown in the gure, bunches of free electrons (the charge per bunch is in the range of tens of pC to about an nC) are accelerated to relativistic speeds and enter a structure known as a wiggler, a periodically spaced arrangement of magnets. As the electron’s trajectory oscillates, they radiate through the well-known phenomenon of synchrotron radiation [3]. is radiation interacts with the magnetic eld of the wiggler to form a ponderomotive wave, which appears at rest with respect to the electrons. is wave causes the electrons to bunch in such a way as to form a distribution that longitudinally is shorter than the electron’s emission wavelength, causing them to emit in phase, that is, coherently.
