VISAR (Velocity Interferometer System for Any Reflector): Line-imaging interferometer
This paper describes a Velocity Interferometer System for Any Reflector (VISAR) technique that extends velocity measurements from single points to a line. Single-frequency argon laser light was focused through a cylindrical lens to illuminate a line on a surface. The initially stationary, flat surface was accelerated unevenly during the experiment. Motion produced a Doppler-shift of light reflected from the surface that was proportional to the velocity at each point. The Doppler-shifted image of the illuminated line was focused from the surface through a push-pull VISAR interferometer where the light was split into four quadrature-coded images. When the surface accelerated, the Doppler-shift caused the interference for each point on each line image to oscillate sinusoidally. Coherent fiber optic bundles transmitted images from the interferometer to an electronic streak camera for sweeping in time and recording on film. Data reduction combined the images to yield a continuous velocity and displacement history for all points on the surface that reflected sufficient light. The technique was demonstrated in an experiment where most of the surface was rapidly driven to a saddle shape by an exploding foil. Computer graphics were used to display the measured velocity history and to aid visualization of the surface motion. 6 refs., 8 figs.
- Research Organization:
- Los Alamos National Lab., NM (USA)
- Sponsoring Organization:
- DOE/DP
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 6706797
- Report Number(s):
- LA-UR-90-2320; CONF-900756--14; ON: DE90015028
- Country of Publication:
- United States
- Language:
- English
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VISAR (Velocity Interferometer System for Any Reflector): Displacement-mode data reduction
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Related Subjects
440800* -- Miscellaneous Instrumentation-- (1990-)
47 OTHER INSTRUMENTATION
ACCELERATION
AMPLITUDES
ARGON
CAMERAS
DOPPLER EFFECT
ELECTRONIC CIRCUITS
ELEMENTS
FABRY-PEROT INTERFEROMETER
FIBER OPTICS
FLUIDS
FOCUSING
FUNCTIONS
GASES
IMAGES
INTERFEROMETERS
LASERS
LENSES
MAPPING
MEASURING INSTRUMENTS
MEASURING METHODS
NONMETALS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
PULSE CIRCUITS
RADIATION DETECTORS
RARE GASES
REFLECTIVITY
RESPONSE FUNCTIONS
SIGNAL CONDITIONERS
STREAK CAMERAS
SURFACE PROPERTIES
VELOCITY
WAVELENGTHS