Selecting Capacitors For High-Voltage X-Ray Power Supplies

As the backbone of the X-ray machine, X-ray tubes produce the radiation that generates the electromagnetic waves known as the “X-ray.” This is done by using a high voltage to accelerate the electrons released by a hot cathode to a high velocity. Those electrons then collide with the anode, which is a metal target usually made of tungsten. This process requires an input voltage typically ranging from 180 to 480 VAC with a power supply that transforms and steps up the voltage to extremely high voltage outputs ranging from 10kV and 120kV DC. A high-level diagram of the power supply required to power the X-ray tubes is shown in Figure 1.

If an X-ray power supply is not correctly designed, there can be serious consequences ranging from deteriorated image quality to the release of excessive radiation that can be harmful to a patient. Therefore, X-ray power supply design must be carefully thought through.