Conduction of electrons through a vacuum

[CSte88]

"Conduction of electrons through a vacuum". Explain.... I'm only looking for about a paragraph to fit in to an atomic physics assignment for college nothing too fancy. As physics is probably my weakest subject all and any help is greatly welcome!

[TonyMcC]

You could look up how a cathode ray tube (CRT) works. Basically electrons have a negative charge and so can be attracted to a positive potential. In a vacuum there is nothing to impede the electrons in their movement toward the positive potential. Electrons can be emitted from their source by heat. In the CRT the heated emitter is known as the cathode and the positive collector of electrons is known as an anode.

[CSte88]

In a vacuum does light not play a part in effecting the electron? Or is the vacuum completely void of light and air? Should have mentioned this was the part I was having particular difficulty with. I vaguely remember being told light can have an affect, but really cant remember exactly what effect if any.

Edited April 1, 2011 by CSte88

[swansont]

Yes, light will scatter off of electrons — Compton scattering. But it would not do much to impede an energetic beam. A practical vacuum will have some amount of air in it, and some electrons will collide. Have you done/heard of the Franck-Hertz experiment?

[TonyMcC]

If going into minor practical effects you might like to consider magnetic fields associated with planets. A magnetic field can deflect electrons from a straight path.

[Riot]

So in layman's terms, Light causes propelling electrons?

[TonyMcC]

Not as far as I know. What I said was a magnetic field can deflect a moving electron.

Edited April 10, 2011 by TonyMcC