Plasmas can sustain even higher gradients, of G 100 GV/m (n0
[1018 cm3])1/2 with a typical plasma density of n0 10171018 -
cm3. The plasmas could also be driven by lasers or e beams,
and in addition by p beams. The repetition rate depends on the
pulse rate of the driver, which for lasers may be up to a few kHz
with an accelerated charge of 50 pC per bunch [46]. ‘‘Unlimited”
acceleration is predicted to be possible [47].