mA

Tube current in milliamperes. Controls the number of X-ray photons produced per unit time.

Why it matters to buyers: mA × exposure time = mA·s, the core dose driver in radiography. Dose reduction algorithms like ASiR let you scan at lower mA.

Why it matters to engineers: mA is constrained by anode heat capacity and generator output. Sustained high-mA fluoro is the #1 tube-life accelerator.