beam collimation

beam collimation

the restriction of x-radiation to the area being examined or treated by confining the beam with metal diaphragms or shutters with high radiation-absorption power. In addition to protecting the patient and others from scatter radiation, beam collimation reduces radiographic density.
References in periodicals archive ?
The system enables the delivery of individual layers of pencil beam spots to precise locations, eliminating the need for beam collimation and compensators to adjust the target area.
The dark room processing faults are also completely eliminated, thus leaving out beam collimation and good technique as the major potential sources of patient's over exposure (6).
The evaluation was based on x-ray beam collimation observed on radiographs stored in the film library of the hospitals, questionnaires administered to radiographers and light beam misalignment test conducted on the x-ray machines.
Should the procedure be prolonged unexpectedly, the radiologist should consider enlarging the X-ray field size or altering the X-ray beam collimation.
Pitch is the distance the table travels per rotation divided by the beam collimation.
Explain the importance of beam collimation and filtration in patient protection.
Proper beam collimation reduces scatter, thereby improving image contrast and effectively reducing patient dose by minimizing unnecessary irradiation of nearby organs outside the area of interest.
Mechanical or optical x-ray beam collimation in conjunction with video camera alignment allows confirmation of specific analysis areas/ features.
Features include mechanical or optical x-ray beam collimation, gas proportional counter or semiconductor x-ray detector, and dual-encoded stage driver options.
At the heart of the system is the new ARIS(TM) Ion Source, which provides exceptional ion beam collimation necessary for within wafer uniformity.
A strip of lead placed on top of the crib at the edge of the inferior border of the x-ray beam collimation (shadow shielding).
We have also routinely generated laser-to-X-ray conversion efficiencies in the 3 percent to 6 percent range (depending upon the laser light wavelength) and, with the demonstrated improvements in X-ray beam collimation technology, we have increased the X-ray power incident on the mask/wafer lithography target 20 to 40 times over this two-year period.