How Does a High-Frequency, High-Power Electron Beam Affect a Vacuum?

[Marianp]

What happens when we send in a vacuum pulsed electron beam with a frequency 1e9Hz and power 1e6MeV?

Thanks.

 

[mfb]

We get a pulsed electron beam with a frequency of 1GHz.
eV is a unit of energy, not of power. Do you mean 1TeV per electron?

Why do you expect something special to happen?

 

[Bob S]

SLAC (Stanford) has accelerated electron beams to about 50 GeV in a straight beam tube using 2.4 GHz microwave power.
CERN (LEP) did accelerate electron beams to about 55 GeV using (I think) 240 (350?) MHz RF power in a 26 km circular accelerator.
The synchrotron radiation losses were extremely high. See http://hyperphysics.phy-astr.gsu.edu/hbase/particles/synchrotron.html

Because the synchrotron radiation power scales as beam energy E⁴, acceleration in a ring to a higher energy would be nearly impossible.

One consequence of synchrotron radiation is the desorption of trapped gasses, etc. from the beam tube walls, leading to vacuum pressure "bumps". which in turn cause beam scattering losses. Synchrotron radiation would be incompatible with superconducting RF cavities, due to the power load on the cryogenic system. Furthermore, at high energies (e.g., 1 TeV), the synchrotron radiation is very tightly focused into a pencil beam, and may melt any beam component it hits. (my guess anyway)..

 

[mfb]

LEP2 accelerated electrons up to ~105 GeV, and synchrotron radiation limited this energy.
Therefore, the next electron/positron collider (ILC) is planned as linear collider, with ~200-400 GeV per beam, depending on the LHC results.