An optical device that generates a parallel beam of light. Often used to compensate for laser beam divergence
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
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
Optical element which produces a light beam in which the rays are (at least very nearly) parallel
A mechanical device, sometimes called a "slit", installed along the trajectory of a beam to reduce the size of the beam Collimators are also useful for removing stray radiation
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 telescope arranged and used to determine errors of collimation, both vertical and horizontal
An 'Infinity Reference Aiming Point' used for the same purpose as the aiming stakes (posts) but with a greater degree of accuracy
An instument that focuses light into a nearly perfect parallel beam (only a laser can achieve a truly perfect collimated beam) When a reticle is incorporated into the design, a collimator can project an image focused on infininty Such an image can be used to check the focus calibration of lenses, and the ground glass depth on reflex cameras
A device that renders divergent or convergent rays more nearly parallel (188) Note: The degree of collimation (parallelism) should be stated
a movable, solid block of material which can be used to limit beam size or to stop it altogether They are sometimes used as safety system critical devices
system for definition of the radiation beam In treatment units this may either be an applicator with a fixed field size (common in low to medium energy x-rays and electron beams) or a set of two orthogonal movable jaws which can define a rectangular field
A tube having a convex lens at one end and at the other a small opening or slit which is at the principal focus of the lens, used for producing a beam of parallel rays; also, a lens so used