Editing Beamline (section)

==Beamline in a particle accelerator==

In [[particle accelerator]]s the beamline is usually housed in a tunnel and/or underground, cased inside a concrete housing for shielding purposes. The beamline is usually a cylindrical metal pipe, typically called a ''beam pipe'', and/or a ''drift tube'', evacuated to a high [[vacuum]] so there are few gas molecules in the path for the beam of accelerated particles to hit, which otherwise could scatter them before they reach their destination.

There are specialized devices and equipment on the beamline that are used for producing, maintaining, monitoring, and accelerating the particle beam. These devices may be in proximity of or attached directly to the beamline. These devices include sophisticated [[transducer]]s, diagnostics (position monitors and [[wire scanner]]s), [[Electrostatic lens|lenses]], [[collimator]]s, [[thermocouple]]s, [[ion pump]]s, [[ion gauge]]s, [[Ionization chamber|ion chambers]] (for diagnostic purposes; usually called "beam monitors"), vacuum valves ("isolation valves"), and [[gate valve]]s, to mention a few.

It is imperative to have all beamline sections, magnets, etc., aligned (often by a [[Surveying|survey]] and an alignment crew by using a [[laser tracker]]), beamlines must be within [[micrometre]] tolerance. Good alignment helps to prevent beam loss, and beam from colliding with the pipe walls, which creates [[secondary emission]]s and/or [[radiation]].