Return-Current-Driven Instabilities of Propagating Electron Beams
Abstract
A stability analysis is performed for the first nine transverse modes (azimuthal mode number plus radial mode number < or = 3) of a self-pinched relativistic electron beam propagating in a collisional plasma. Only frequencies omega in the range omega tau sub d << 1 are considered, where tau sub d is the dipole magnetic decay length. For such modes, the presence of plasma return current is the only destabilizing mechanism. Paraxial flow, space charge neutrality, and a flat radial profile of beam density are also assumed. Within these limitations an exact analysis of the linearized Vlasov stability problem is carried out in closed form. For each mode, the instability threshold, growth rate, and conditions for oscillatory vs. pure growth are determined. For beams with a moderate return current fraction, the hose, sausage and axial hollowing modes appear to be particularly dangerous.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 05, 1982
- Accession Number
- ADA111911
Entities
People
- Han S. Uhm
- Mártin Lampe
Organizations
- United States Naval Research Laboratory