I understand that a particle /linear accerator would be the logical source supplying the energetic, free electrons to the LASER cavity, and that super-cooled, super-conducting magnets (like used in an accelerator or magnetic resonance imaging system) can be used as “wigglers” to tune the wavelength of the emitted photons, but how in “Zues’ name” do the electrons that were once free and energetic get recycled into the particle accerator to be reenergized? How does one avoid destroying the mirrors by the tremendous energy and “hot spots”?