Optical alignment techniques for line-imaging velocity interferometry and line-imaging self-emulsion of targets at the National Ignition Facility (NIF)
The National Ignition Facility (NIF) requires optical diagnostics for measuring shock velocities in shock physics experiments. The Velocity Interferometer System for Any Reflector (VISAR) measures shock velocities, shock breakout times, and emission of 1- to 5-mm targets at a location remote to the NIF target chamber. Three optical systems using the same vacuum chamber port each have a total track of 69 feet. All optical lenses are on kinematic mounts or sliding rails, enabling pointing accuracy of the optical axis to be checked. Counter-propagating laser beams (orange and red) align these diagnostics to a listing of tolerances. The orange alignment laser is introduced at the entrance to the two-level interferometer table and passes forward through the optical systems to the recording streak cameras. The red alignment laser is introduced in front of the recording streak cameras and passes in the reverse direction through all optical elements, out of the interferometer table, eventually reaching the target chamber center. Red laser wavelength is selected to be at the 50 percent reflection point of a special beamsplitter used to separate emission light from the Doppler-shifted interferometer light. Movable aperture cards, placed before and after lens groups, show the spread of alignments spots created by the orange and red alignment lasers. Optical elements include 1- to 15-inch-diameter mirrors, lenses with up to 10.5-inch diameters, beamsplitters, etalons, dove prisms, filters, and pellicles. Alignment of more than 75 optical elements must be verified before each target shot. Archived images from eight alignment cameras prove proper alignment before each shot.
- Research Organization:
- National Security Technologies, LLC (NSTec), Mercury, NV (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NA)
- DOE Contract Number:
- DE-AC52-06NA25946
- OSTI ID:
- 946608
- Report Number(s):
- DOE/NV/25946-128; TRN: US0900992
- Resource Relation:
- Conference: 2007 SPIE Optics and Photonics Conference, San Diego, CA, August 26-30, 2007; Related Information: Abstract
- Country of Publication:
- United States
- Language:
- English
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Optical Alignment Techniques for Line-Imaging Velocity Interferometry and Line-Imaging Self-Emission of Targets at the National Ignition Facility (NIF)
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Related Subjects
GENERAL PHYSICS
ACCURACY
ALIGNMENT
APERTURES
CAMERAS
INTERFEROMETERS
INTERFEROMETRY
LASERS
LENSES
MIRRORS
OPTICAL SYSTEMS
OPTICS
PHYSICS
PRISMS
REFLECTION
STREAK CAMERAS
TARGET CHAMBERS
TARGETS
US NATIONAL IGNITION FACILITY
VELOCITY
WAVELENGTHS
VISAR
optical relay
interferometer
National Ignition Facility (NIF)
streak camera
optical alignment
optical tolerancing