THE EFFECT OF ELECTRON-BEAM ON THE ELECTRON-HOLE IN A PLASMA

An electron hole is discussed theoretically in an electron beam-plasma system. The nonlinear dispersion relation for the electron hole along with the conditions on the existence of the electron hole is investig ated numerically. It is found that depending upon the beam parameters and radial boundary there are two regions where the electron hole can be formed. It is also seen that the upper limit on Mach number of the electron hole does not vanish even in the presence of the electron bea m. The electron holes of high Mach number are possible only in the pre sence of an electron beam.