A device for limiting the effects of beam spread.

A device used to define the size and shape of a radiation beam in radiation therapy treatment machines; A collimator typically consists of large blocks of heavy metals, such as steel or tungsten, moved by mechanical motors to define rectangular fields; see IMRT

A device for confining the elements of a beam of radiation within an assigned solid angle.

a device for obtaining a particle beam of limited cross section

A device that produces a parallel beam of radiation. This is either done by refraction (as with light), bending the rays until they are parallel using a system of lenses or (as with gamma rays) by absorbing (using a lead grid system) all of those rays that are not travelling parallel to one another.

A device for producing beams of parallel rays of light or other electromagnetic radiation.

a small telescope attached to a large telescope to use in setting the line of the larger one

optical device consisting of a tube containing a convex achromatic lens at one end and a slit at the other with the slit at the focus of the lens; light rays leave the slit as a parallel beam

a device that confines and directs X-ray to a specific region

a device that defines and limits a field of radiation

a device that kind of straightens up beams of light and makes them all point in the same direction

a device used to filter a stream of rays (such as x-rays) so that only those travelling parallel to each other in a certain direction are allowed

an instrument which produces a beam of light which appears to come from infinity

a tool used to "collimate" or align the optical system in a telescope

A device made from radiation absorbent material such as lead or tungsten, designed to limit and define the direction and angular divergence of the radiation beam.

device used to reduce the noise effects of radiation hitting a detector crystal ring

multileaf Unit that shapes radiation by computer digitization, replacing custom blocking. A further refinement of this device is called the miniature multileaf collimator.

A device that organizes radiation such that only parallel rays or beams emanate.

a device which collimates (makes parallel) incoming radiation; some collimators absorb the incoming radiation to ensure the detected photons are from a small angle in the sky, others deflect light to ensure that it is parallel when it hits the detector

In shooting, an optical device used to roughly align the sights with the bore of a rifle or handgun. Essentially, a collimator allows bore sighting without having to see through the barrel.

Optical device consisting of two lenses separated by the sum of their focal length. It is used to provide desired beam diameter to meet specific beam delivery requirements.

An optical instrument consisting of a well-corrected objective lens with an illuminated slit or reticle [reticule ???] at its focal plane. Collimators are used in lens testing to determine focal lengths, and in other meteorological applications where a distant object at a known location is required.

The device used for collimation. The Hi·Art System has two collimating devices: the primary collimator, or jaws; and the multileaf collimator (MLC).

In neutron, X-ray and gamma ray optics, a collimator is a device that filters a stream of rays so that only those travelling parallel to a specified direction are allowed through. Collimators are used in neutron, X-, and gamma-ray optics because it is not yet possible to focus radiation with such short wavelengths into an image through the use of lenses as is routine with electromagnetic radiation at optical or near-optical wavelengths.