Accelerating particles

Posted in Physics, Charge and field

Charged particles such as electrons can be accelerated by putting a potential difference across two electrodes

Negative charges (e.g. electrons) are accelerated towards the positive electrode whilst positive charges (e.g. protons) are accelerated towards the negative electrode.

accelerating particles

In this acceleration particles gain kinetic energy which, in a vacuum, is equal to the loss in electrical potential energy the particle had. Algebraically:

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This equation can be rearranged to give an equation which allows the speed of an accelerated particle to be calculated:

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Old style CRT televisions work by firing a beam of electrons using what is known simply as an 'electron gun'. These use the same idea described above except that the electrodes are tubes rather than flat plates as this diagram shows:

Electron gun example

In this case a negatively charged particle is accelerated towards to the positively charged electrode. This idea is what powers linear accelerators, by placing a number of such electrodes in a line electrons can be accelerated multiple times.