What is the charge of cathodes in an x-ray tube?

In an x-ray tube, cathodes are the negatively charged electrodes. Their main role is to emit electrons when heated, a process known as thermionic emission. These electrons are then directed towards the anode, where they strike a target material, typically made of tungsten, to produce x-rays.

The negative charge of the cathode is critical for the operation of the x-ray tube. It establishes the electric field that drives the electrons toward the positive anode. This flow of electrons from cathode to anode is fundamental to generating x-rays. Understanding the charge of the cathode helps grasp the entire process of x-ray production and the functioning of electronic components in the device.

In contrast, the anode carries a positive charge, neutral electrodes would not function in this context, and variable charge is not applicable as the charge state of cathodes is consistently negative during operation.