"X-ray units require a high voltage generator to achieve the necessary power required of an x-ray tube. AC power will supply x-ray units with sinusoidal currents, resulting in 'peaks and troughs', limiting an x-ray tube to produce x-rays only half of the 1/60th of s second cycle."
"A single-phase high voltage generator converts this AC power into a half or full wave rectified supply with a measure in the thousands of volts."
"The advancement of high voltage generators from single-phase to three-phase to constant potential generators have overcome this 'voltage ripple' creating a continuous, uninterrupted voltage. Modern x-ray units, which largely utilise, constant potential generators do not have 'voltage ripple' and consequently employ the term kV rather than kVp."
"The half wave rectification results in a peak voltage that will dip to zero, reoccurring; this will consequently have an effect on the behaviour of radiation produced and hence the name kilovoltage peak (kVp) was born."