From a scientific and technological standpoint, their work is outstanding. As an electron beam passes between the copper colored magnets shown here, it changes directions. The poles of the magnets alternate, so the electron beam is forced to wiggle up and down. Any wiggling electric charge emits electromagnetic radiation. The type of electromagnetic radiation produced depends on how quickly the charge wiggles.
Slower wiggles can make radio waves or microwaves, while faster wiggles can make x-rays.
The FEL's electron beam will produce infrared light and a future upgrade will allow it to produce ultraviolet light. The congressional stipend will go to upgrade JLab's FEL power more than 10-fold, from a current level of 1.72 kilowatts to perhaps as high as 20 kilowatts. At 20,000 watts, the FEL will have more than enough power to disrupt internal electronics or perhaps even burn through fuel tanks. Even at lower energies, the device would still work to deter attack. What you re after is disabling the infrared sensors on an incoming missile to prevent it from sneaking up your airplane tailpipe or blowing up your smokestack on the ground.