Beamline - Beamline in A Particle Accelerator

Beamline in A Particle Accelerator

In particle accelerators the beamline is usually housed in a tunnel and/or underground, cased inside a cement housing. The beamline is usually cylindrical metal. Typical names include, beam pipe, and/or a blank section called a drift tube. This entire section must be under a good vacuum in order to have a large mean free path for the beam.

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 or attached to the beamline. These devices include sophisticated transducers, diagnostics (position monitors and wire scanners), lenses, collimators, thermocouples, ion pumps, ion gauges, ion chambers (sometimes called "beam loss monitors"), vacuum valves ("isolation valves"), and gate valves, to mention a few. There are also water cooling devices to cool the dipole and quadrupole magnets. Positive pressure, such as that provided by compressed air, regulates and controls the vacuum valves and manipulators on the beamline.

It is imperative to have all beamline sections, magnets, etc., aligned by a survey and alignment crew by using a laser tracker. All beamlines must be within micrometre tolerance. Good alignment helps to prevent beam loss, and beam from colliding with the pipe walls, which creates secondary emissions and/or radiation.