The Electron Linear Accelerator as a Pulsed Radiation Source

One of the inherent properties of the electron linear accelerator is that it produces radiation in pulses whose duration is less than the pulse duration of the radio frequency source from which it is fed. In practice the pulse length lies in the range from one to five microseconds. However, by independently pulsing the electron source or injector, intense pulses of radiation of duration 0.1 μsec or less can be easily achieved and the lower limit is set only by stray capacitance effects. The radiation produced can be electrons, X rays, or neutrons (by gamma-n reaction). One of the more important practical applications in nuclear research is as a pulsed neutron source in time-of-flight neutron spectroscopy where the short duration and high flux, when used with appropriate analyzing circuitry, provide a spectrometer of high resolving power in the intermediate neutron range. Short bursts of radiation also find application in radio-chemistry where physicochemical changes often occur in a very short interval after the absorption of radiation.