Laser-matter interaction at intensities of 10 sup 12 W/cm sup 2 and below

Conference · Mon Jan 01 04:00:00 EST 1990

OSTI ID:7070642

Goldman, S R; Dingus, R S; Kirkpatrick, R C; Kopp, R A; Stover, E K; Watt, R G

For single pulsed laser-matter interactions at sufficiently high intensity, the electron density in the ablated vapor is large enough to absorb the laser radiation before it can reach the dense target material. The resulting interaction can be described in terms of energy flows: laser energy is absorbed in the plasma in front of the target and reappears as thermal electron energy and secondary radiation, part of which impinges upon and heats the dense target material at the dense material-vapor interface. This heating in turn drives ablation, thereby providing a self-consistent mass source for the laser absorption, energy conversion, and transmission. Under typical conditions of laser intensity, pulse width and spot size, the flow patterns can be strongly two-dimensional. We have modified the inertial confinement fusion code LASNEX to simulate gaseous and some dense material aspects for the relatively low intensity, long-pulse-length conditions to interest in many laser-related applications. The unique aspect to our treatment consists of an ablation model which defines a dense material vapor interface and then calculates the mass flow across this interface. The model, at present, treats the dense material as a rigid, two-dimensional simulational mass and heat reservoir, suppressing all hydrodynamical motion in the dense material. The modeling is being developed and refined through simulation of experiments, as well as through the investigation of internal inconsistencies, and some simulations of model problems. 5 refs., 14 figs., 1 tab.

• Research Organization: Los Alamos National Lab., NM (USA)
• Sponsoring Organization: DOD; DOE/DP
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 7070642
• Report Number(s): LA-UR-90-496; CONF-900368--1; ON: DE90007536
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
426002* -- Engineering-- Lasers & Masers-- (1990-)
656003 -- Condensed Matter Physics-- Interactions between Beams & Condensed Matter-- (1987-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
99 GENERAL AND MISCELLANEOUS
990200 -- Mathematics & Computers
ABLATION
ABSORPTION
BEAM TRANSPORT
COMPARATIVE EVALUATIONS
COMPUTER CODES
COMPUTERIZED SIMULATION
DENSITY
ELECTROMAGNETIC RADIATION
END EFFECTS
ENERGY TRANSPORT
FLUID MECHANICS
FLUIDS
FORECASTING
GASES
HYDRODYNAMICS
INTERFACES
L CODES
LASER RADIATION
MATTER
MEASURING METHODS
MECHANICS
PHYSICAL PROPERTIES
PRESSURE EFFECTS
PULSES
RADIATION FLUX
RADIATIONS
RECOMMENDATIONS
RELIABILITY
SIMULATION
TEMPERATURE EFFECTS
TWO-DIMENSIONAL CALCULATIONS
VAPORS
VERIFICATION
WAVELENGTHS