The model 642 Extreme Ultraviolet (EUV) light source from McPherson, Inc. (Chelmsford, MA) utilizes a filament to produce electrons that are accelerated toward a target by high voltage. It is stable, debris-free, and controllable. The device features two symmetrical output beams. The source is not sealed, allowing users to exchange anodes to produce desired wavelengths (e.g., boron for 6.7 nm, silicon for 13.5 nm, aluminum for 17.1 nm, etc.). The interactions of the electrons as they impact a solid target (anode) cause excitation of the atomic inner shells with subsequent decay and emission.