The upper limit of the electron hole Mach number under the presence of an electron beam is discussed theoretically by solving the Poisson equation. When the beam component exists in plasmas, a new hole solution appears owing to shielding effects of the beam electrons. The hole speed can greatly exceed the critical Mach number M0 equivalent to 1.3. For the beam component ratio above approximately 0.22 the upper limit of the Mach number intrinsically vanishes when the beam temperature is equal to that of the bulk. The transverse effect due to a finite radial wave number K strongly modifies the parameter regimes for the hole solution.
ASJC Scopus subject areas
- Nuclear Energy and Engineering
- Condensed Matter Physics