If the mA is doubled, what happens to the number of x-ray photons emitted from the tube?

When the milliampere (mA) setting on an x-ray machine is doubled, the number of x-ray photons emitted from the tube also doubles. This is because mA is a measure of the tube current, which directly influences the amount of radiation produced.

In radiographic imaging, the amount of exposure is proportional to the current passing through the x-ray tube. Essentially, increasing the mA increases the number of electrons that are available to be converted into x-ray photons during each exposure. As a result, if the mA is doubled, twice as many x-ray photons are produced in the same amount of time, leading to a corresponding increase in exposure.

This direct correlation means that changes in mA will have a predictable effect on the quantity of x-ray photons generated, confirming that doubling the mA results in doubling the photon output.