Acceleration wake-field enhancement of excited by long relativistic electron bunch owing to self-modulation

Charged particle acceleration by charge density waves in a plasma and in uncompensated charged beams appears to be a most promising trend in the collective methods of acceleration. Here, we consider two different regimes with high amplitudes of plasma wake fields that are employed in accelerator physics. The first regime makes use of an extended short beam, then the high-amplitude waves excited by this beam and having high-gradient longitudinal electric fields can be used to accelerate other bunches. In the second case, a strong focusing can be attained with a long narrow beam, making use of its intrinsic magnetic field which is unbalanced because of space charge compensation by the plasma