  a linear particle accelerator (often shortened to linac) is a type of particle accelerator that greatly increases the kinetic energy of charged subatomic particles or ions by subjecting the charged particles to a series of oscillating electric potentials along a linear beamline; this method of particle acceleration was invented by leÃ³ szilÃ¡rd. it was patented in 1928 by rolf widerÃ¸e, who also built the first operational device and was influenced by a publication of gustav ising. linacs have many applications: they generate x-rays and high energy electrons for medicinal purposes in radiation therapy, serve as particle injectors for higher-energy accelerators, and are used directly to achieve the highest kinetic energy for light particles (electrons and positrons) for particle physics. the design of a linac depends on the type of particle that is being accelerated: electrons, protons or ions. linac range in size from a cathode ray tube (which is a type of linac) to the  linac at the slac national accelerator laboratory in menlo park, california. ==construction and operation== thumb|300px|schema of a linear accelerator a linear particle accelerator consists of the following elements: *the particle source. the design of the source depends on the particle that is being moved. electrons are generated by a cold cathode, a hot cathode, a photocathode, or radio frequency (rf) ion sources. protons are generated in an ion source, which can have many different designs. if heavier particles are to be accelerated, (e.g., uranium ions), a specialized ion source is needed. *a high voltage source for the initial injection of particles. *a hollow pipe vacuum chamber. the length will vary with the application. if the device is used for the production of x-rays for inspection or therapy the pipe may be only 0.5 to 1.5 meters long. if the device is to be an injector for a synchrotron it may be about 
Accelerator_physics Types_of_magnets X-rays