Actual Focal Spot Size: The size of the area on the target, that is exposed to an amount of electrons.

Anode: The positively charged electrode of the x-ray tube.

Artifact: Any unwanted image on a radiograph.

Attenuation: The reducing of energy of the primary beam as it passes through the atomic part.

Automatic Exposure Control (AEC): A device that is used to control radiographic density by terminating the exposure due to the amount of radiation reaching the image receptor.

BackUp Time: The maximum amount of time set that will terminate the exposure when using an AEC.

Base Plus Fog (B+F): The minimum amount of optical density on a film.

Body Habitus: The general size of one’s body size and shape.

kVp: (kilovoltage peak): kvp is the quality of photons in the x-ray beam. This is the controlling factor for contrast, but kVp also has an effect on the density of the image.

Cathode: The negatively charged electrode of the x-ray tube.

Contrast: The different in two adjacent densities.

Density: The overall blackness of an image.

mAs (milliamperage per second): The quantity of electrons produced by the x-ray tube in a given amount of time. This is the main controling factor for density.

Focusing Cup: Is a negatively charged cup, that is used to focus the electron stream.

Dual-Focus: Meaning having two filaments.

Leakage radiation: Any radiation that is leaked through the x-ray tube other than the primary beam.

Deadman Switch: A switch that is used to make the x-ray exposure, but when let off of the exposure is immediately terminated.

Thermionic Emission: The boiling off of electrons at the filament.

Tube Current: The electron flow from cathode to anode.

Effective Focal Spot Size: The size of the focal spot under the x-ray tube.

Target: The part of the Anode that is actually struck by the electron beam.

SID (source to image receptor distance): The distance between the source of radiation and the image receptor.

OID (object to image receptor distance): The distance between the objected being imaged and the image receptor.

Compensating Filter: A compensating filter can be added to the primary beam to compensate the intensity of the x-ray beam.