Self-focusing and ion wave generation in laser-produced plasmas

Journal Article · Mon Aug 01 04:00:00 EDT 1988 · Phys. Fluids; (United States)

DOI:https://doi.org/10.1063/1.866633· OSTI ID:7184760

Rankin, R; Marchand, R; Capjack, C E

Two-dimensional hydrodynamic simulations of laser light self-focusing in a hydrogen plasma are presented. The simulation code includes a model for laser beam propagation which accounts for inverse bremsstrahlung absorption, refraction, diffraction, and ponderomotive forces. A Gaussian hot spot, superimposed upon a collimated, spatially uniform laser beam, is used to initiate self-focusing. Intense filaments provide a driving source for ion waves near the axis of the laser beam. The radially propagating ion waves cause spatiotemporal modulations of the flux where it is initially uniform, as well as the more usual focusing that occurs along the axis. Some of the factors affecting the generation of the ion waves are considered. In particular, the effect of changing the amplitude and width of the imposed nonuniformity is investigated. The intensity thresholds for thermal and ponderomotively driven self-focusing have also been determined by artificially turning the ponderomotive force on and off.

• Research Organization: Department of Electrical Engineering, University of Alberta, Edmonton, Alberta T6G 2G7, Canada
• OSTI ID: 7184760
• Journal Information: Phys. Fluids; (United States), Journal Name: Phys. Fluids; (United States) Vol. 31:8; ISSN PFLDA
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700108* -- Fusion Energy-- Plasma Research-- Wave Phenomena
ABSORPTION
BREMSSTRAHLUNG
COHERENT SCATTERING
DIFFRACTION
ELECTRIC POTENTIAL
ELECTROMAGNETIC RADIATION
ENERGY ABSORPTION
FLUID MECHANICS
HYDRODYNAMICS
ION WAVES
LASER RADIATION
LASER-PRODUCED PLASMA
MECHANICS
NONLINEAR OPTICS
OPTICS
PLASMA
PLASMA WAVES
RADIATIONS
REFRACTION
SCATTERING
SIMULATION
TWO-DIMENSIONAL CALCULATIONS