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Q:
Thanks for helping me concerning electron beam in vacuum.
If a beam of e- loses no energy in vacuum, can we transmit electric energy in this way without loss? I find it quite ridiculous to associate vacuum with superconduction, but I cannot point out the flaw.
- Allan (age 29)
Hong Kong
A:
Yup, you sure can transmit energy in this manner. We always complain
about the classification of energy as "electric" or some other kind.
Electron accelerators give a large amount of kinetic energy to the
electrons they accelerate. I think the standard line about the linear
collider idea is that each bunch of electrons that goes down the
accelerator has the same energy content as a cup of yogurt (chemical
energy in the yogurt, not rest mass! And the energy of the electron
beam is almost entirely kinetic).
A practical worry -- you usually have to get the electrons back to
the source to complete a circuit. This step could be lossy. If there's
an electric field pointing in one direction you have to find some way
of overcoming it.
Tom
p.s.- This is NOT superconductivity. It's not a way to make a
circuit in which current flows almost indefinitely. If the electrons
have to bounce of of something to make the return trip, they will lose
some energy in the bounce.
mike w.
(published on 10/22/2007)
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