Abstract: A system for generating tunable pulsed monochromatic X-rays includes a tabletop laser emitting a light beam that is counter-propagated against an electron beam produced by a linear accelerator. X-ray photon pulses are generated by inverse Compton scattering that occurs as a consequence of the “collision” that occurs between the electron beam and IR photons generated by the laser. The system uses a novel pulse structure comprising, for example, a single micropulse. In this way, pulses of very short X-rays are generated that are controllable on an individual basis with respect to their frequency, energy level, “direction,” and duration.