CONTINUUM
The continuum is the background radiation produced during the production of the characteristic x-rays. It is generated as the high energy electrons from the gun interact with the nuclei of the target atoms, and their trajectories are altered by the positive charge of the nuclei. When the electron trajectory bends, x-ray radiation is emitted at an energy level that ranges on a continuous scale ( hence continuum) from a minimal low value, up to a maximum of the acceleration voltage value. Also known as Bremstrahlung (literally "braking radiation").