Accession Number:

ADA167134

Title:

The VIPER Conductivity Model

Descriptive Note:

Memorandum rept.

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON DC

Personal Author(s):

• Slinker, S. P.
• Hubbard, R. F.

Report Date:

1986-04-24

Pagination or Media Count:

20.0

Abstract:

Beam propagation codes such as the hose simulation code VIPER require simple models for treating the generation of conductivity by the bean pulse. The VIPER conductivity model calculates the electron density n sub e r,zeta,z where zeta ct-z is the distance from the beam head. The rate equation for n sub e treaties beam impact ionization, avalanche ionization, and recombination. Rate coefficients and momentum transfer frequency are functions of the electron temperature T sub e which is itself estimated from the ratio of the local electric field to the neutral gas density. Since VIPER treats both monopole and dipole beam dynamics, the perturbed or dipole conductivity must also be calculated. Benchmark comparisons between the VIPER model and more elaborate treatments of beam-generated conductivity are also presented. Keywords Air chemistry Beam propagation Charge particle beam Beam generated ionization Beam generated conductivity Intense relativistic electron beam.

Descriptors:

• *AVALANCHE EFFECT(ELECTRONICS)
• *CONDUCTIVITY
• *ELECTRIC FIELDS
• *IONIZATION
• BEAMS(RADIATION)
• BEANS
• CODING
• COEFFICIENTS
• DENSITY
• DIPOLES
• DYNAMICS
• ELECTROMAGNETIC WAVE PROPAGATION
• ELECTRON DENSITY
• ELECTRON ENERGY
• EQUATIONS
• FREQUENCY
• GASES
• HEAD(ANATOMY)
• HOSES
• IMPACT
• MODELS
• MOMENTUM TRANSFER
• NEUTRAL
• PERTURBATIONS
• PULSES
• RATES
• RATIOS
• SIMULATION

Subject Categories:

• Electricity and Magnetism
• Particle Accelerators

Distribution Statement:

APPROVED FOR PUBLIC RELEASE