How Does the X-ray Tube Operate?

When we turn on the x-ray tube, we activate the low voltage circuit; this will preheat the filament to a specific temperature to generate electrons through thermionic emission. The number of electrons generated is proportional to the temperature of the filament.^1,5,10,11 The timer and high voltage circuit are activated simultaneously, and the electrons at the filament will begin to travel at high speed towards the target. The higher the voltage between the cathode and the anode, the greater the speed at which the electrons travel.^6,7,9,11,12 The number of electrons traveling from the cathode to the anode is called the tube current.^7,9 The maximum energy output of the x-ray tube is called the kilovolt peak or kVp.^1,2,3,4