Electron beam hollowing instability simulations

Journal Article · Sun Feb 01 04:00:00 EST 1987 · Phys. Fluids; (United States)

DOI:https://doi.org/10.1063/1.866355· OSTI ID:6766197

Godfrey, B B

Intense electron beam hollowing instabilities, although routinely observed in axisymmetric computer simulations of beam propagation in air, are not often seen in experiments because of competing nonaxisymmetric effects. Recent experiments with the IBEX accelerator 4 MeV, 70 kA electron beam (R. B. Miller, M. G. Mazarakis, J. W. Poukey, and R. J. Adler, IEEE Trans. Nucl. Sci. 30, 2722 (1983)) provided detailed measurements of hollowing instability scaling over the pressure range of 10--80 Torr. Simulations performed in support of those experiments are reported here. Both experiment and simulation show large amplitude hollowing at the lowest pressures, decreasing in magnitude as the pressure is increased. The instability is suppressed above about 120 Torr. In addition, the simulations indicate that hollowing can be reduced by matching the beam radius at injection with its equilibrium value in air. The good agreement between experiment and simulation validates existing hollowing instability scaling laws.

• Research Organization: Mission Research Corporation, Albuquerque, New Mexico 87106
• OSTI ID: 6766197
• Journal Information: Phys. Fluids; (United States), Journal Name: Phys. Fluids; (United States) Vol. 30:2; ISSN PFLDA
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700107* -- Fusion Energy-- Plasma Research-- Instabilities
ACCURACY
AIR
BEAM INJECTION
BEAM-PLASMA SYSTEMS
BEAMS
CORRELATIONS
ELECTRON BEAM INJECTION
ELECTRON BEAMS
EQUILIBRIUM
FLUIDS
GASES
INSTABILITY
LEPTON BEAMS
LOW PRESSURE
PARTICLE BEAMS
PLASMA INSTABILITY
PRESSURE DEPENDENCE
SCALING LAWS
SIMULATION