An assembly of devices designed to produce high-energy electrons to yield high-energy x-rays used for therapeutic applications, primarily to treat cancer. It provides a uniform radiation field of uniform intensity and predictable energy level, in a beam with well defined dimensions. The principle of operation is linear acceleration of electrons by means of electromagnetic (EM) microwaves. The output is used as a treatment beam on the patient, either directly or after passing a suitable target. The system typically includes signal analysis and display devices, patient and device supports, and software.