Combining a thermal-imaging diagnostic with an existing imaging VISAR diagnostic at the National Ignition Facility (NIF)

Conference · Sat Jan 01 00:00:00 EST 2005

OSTI ID:935048

Malone, Robert M; Celesteb, John R; Celliers, Peter M; Froggeta, Brent C; Guyton, Robert L; Kaufman, Morris I; Lee, Tony L; MacGowan, Brian J; Ng, Edmund W; Reinbachs, Imants P; Robinson, Ronald B; Seppala, Lynn G; Tunnell, Tom W; Watts, Phillip W

Optical diagnostics are currently being designed to analyze high-energy density physics experiments at the National Ignition Facility (NIF). Two independent line-imaging Velocity Interferometer System for Any Reflector (VISAR) interferometers have been fielded to measure shock velocities, breakout times, and emission of targets having sizes of 1–5 mm. An 8-inch-diameter, fused silica triplet lens collects light at f/3 inside the 30-foot-diameter NIF vacuum chamber. VISAR recordings use a 659.5-nm probe laser. By adding a specially coated beam splitter to the interferometer table, light at wavelengths from 540 to 645 nm is spilt into a thermal-imaging diagnostic. Because fused silica lenses are used in the first triplet relay, the intermediate image planes for different wavelengths separate by considerable distances. A corrector lens on the interferometer table reunites these separated wavelength planes to provide a good image. Thermal imaging collects light at f/5 from a 2-mm object placed at Target Chamber Center (TCC). Streak cameras perform VISAR and thermal-imaging recording. All optical lenses are on kinematic mounts so that pointing accuracy of the optical axis may be checked. Counter-propagating laser beams (orange and red) are used to align both diagnostics. The red alignment laser is selected to be at the 50 percent reflection point of the beam splitter. This alignment laser is introduced at the recording streak cameras for both diagnostics and passes through this special beam splitter on its way into the NIF vacuum chamber.

• Research Organization: Bechtel Nevada; Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: DE-AC08-96NV11718
• OSTI ID: 935048
• Report Number(s): DOE/NV/11718-1013; TRN: US0804047
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ACCURACY
ALIGNMENT
INTERFEROMETERS
LASERS
LENSES
PHYSICS
PROBES
REFLECTION
SILICA
STREAK CAMERAS
TARGET CHAMBERS
TARGETS
TRIPLETS
US NATIONAL IGNITION FACILITY
VELOCITY
WAVELENGTHS
VISAR
interferometer
optical relay
National Ignition Facility (NIF)
streak camera