Which factor primarily affects the quantity of radiation produced in an X-ray tube?

The quantity of radiation produced in an X-ray tube is primarily determined by the milliampere-seconds (mAs). The mAs is a product of the milliamperage (mA), which controls the current passing through the X-ray tube, and the exposure time in seconds. When the mAs increases, it directly correlates to an increase in the number of X-ray photons produced.

Higher mAs results in a greater number of electrons being accelerated across the tube, leading to a higher output of radiation. This increase in radiation is fundamental for ensuring sufficient exposure for imaging, especially in situations where higher density or more opaque structures are being imaged.

While kVp is essential for determining the energy and penetrating power of the X-rays produced, it does not primarily influence the quantity; instead, it affects the quality of the radiation. Exposure time alone can influence quantity in conjunction with mA, but it is the combination expressed in mAs that is the most straightforward measure of radiation output. Filtration, on the other hand, serves to improve the quality of the beam by removing lower-energy photons, but it does not increase the quantity of radiation produced by the X-ray tube itself.