ICALEPCS2013 - List of Authors (Rushford, M.C.)

Paper

Title

Page

Image Analysis for the Automated Alignment of the Advanced Radiography Capability (ARC) Diagnostic Path*

1274

R.S. Roberts, A.A.S. Awwal, E.S. Bliss, R.R. Leach, M.C. Rushford, K.C. Wilhelmsen
LLNL, Livermore, California, USA

Funding: *This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. #LLNL-ABS-631616
The Advanced Radiographic Capability (ARC) at the National Ignition Facility was developed to produce a sequence of short laser pulses that are used to backlight an imploding fuel capsule. This backlighting capability will enable the creation of a sequence of radiographs during capsule implosion and provide an unprecedented view into the dynamics of the implosion. A critical element of the ARC is the diagnostic instrumentation used to assess the quality of the pulses. Pulses are steered to the diagnostic package through a complex optical path that requires precision alignment. A central component of the alignment system is the image analysis algorithms, which are used to extract information from alignment imagery and provide feedback for the optical alignment control loops. Alignment imagery consists of complex patterns of light resulting from the diffraction of pilot beams around cross-hairs and other fiducials placed in the optical path. This paper describes the alignment imagery, and the image analysis algorithms used to extract the information needed for proper operation of the ARC automated alignment loops.

Poster THPPC085 [3.236 MB]

THPPC141

Automatic Alignment Upgrade of Advanced Radiographic Capability for the National Ignition Facility

1384

K.C. Wilhelmsen, E.S. Bliss, G.K. Brunton, B.T. Fishler, R.R. Lowe-Webb, D.L. McGuigan, R.S. Roberts, M.C. Rushford
LLNL, Livermore, California, USA

Funding: This work was performed under the auspices of the Lawrence Livermore National Security, LLC, (LLNS) under Contract No. DE-AC52-07NA27344. #LLNL-ABS-632633
For many experiments planned on the National Ignition Facility (NIF), high-energy x-ray backlighters are an important diagnostic. NIF will be deploying this year a new Advanced Radiographic Capability (ARC) for generating these high-energy short-pulses. The precision of the Automatic Alignment (AA) for ARC is an important element in the success of the enhancement. A key aspect of the ARC AA is integration of the new alignment capabilities without disturbing the existing AA operations of NIF. Small pointing tolerances of 5 micron precision to a 10 micron target are required. After main amplification the beams are shortened by up to 1,000x in time in the ARC compressor vessel and aimed at backlighter targets in the NIF target chamber. Alignment Stability and Verification of the compressor gratings is critical to ensuring the ARC pulses meet their experimental specifications.

Poster THPPC141 [4.485 MB]

Paper	Title	Page
THPPC085	Image Analysis for the Automated Alignment of the Advanced Radiography Capability (ARC) Diagnostic Path*	1274
	R.S. Roberts, A.A.S. Awwal, E.S. Bliss, R.R. Leach, M.C. Rushford, K.C. Wilhelmsen LLNL, Livermore, California, USA
	Funding: *This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. #LLNL-ABS-631616 The Advanced Radiographic Capability (ARC) at the National Ignition Facility was developed to produce a sequence of short laser pulses that are used to backlight an imploding fuel capsule. This backlighting capability will enable the creation of a sequence of radiographs during capsule implosion and provide an unprecedented view into the dynamics of the implosion. A critical element of the ARC is the diagnostic instrumentation used to assess the quality of the pulses. Pulses are steered to the diagnostic package through a complex optical path that requires precision alignment. A central component of the alignment system is the image analysis algorithms, which are used to extract information from alignment imagery and provide feedback for the optical alignment control loops. Alignment imagery consists of complex patterns of light resulting from the diffraction of pilot beams around cross-hairs and other fiducials placed in the optical path. This paper describes the alignment imagery, and the image analysis algorithms used to extract the information needed for proper operation of the ARC automated alignment loops.
	Poster THPPC085 [3.236 MB]

THPPC141	Automatic Alignment Upgrade of Advanced Radiographic Capability for the National Ignition Facility	1384
	K.C. Wilhelmsen, E.S. Bliss, G.K. Brunton, B.T. Fishler, R.R. Lowe-Webb, D.L. McGuigan, R.S. Roberts, M.C. Rushford LLNL, Livermore, California, USA
	Funding: This work was performed under the auspices of the Lawrence Livermore National Security, LLC, (LLNS) under Contract No. DE-AC52-07NA27344. #LLNL-ABS-632633 For many experiments planned on the National Ignition Facility (NIF), high-energy x-ray backlighters are an important diagnostic. NIF will be deploying this year a new Advanced Radiographic Capability (ARC) for generating these high-energy short-pulses. The precision of the Automatic Alignment (AA) for ARC is an important element in the success of the enhancement. A key aspect of the ARC AA is integration of the new alignment capabilities without disturbing the existing AA operations of NIF. Small pointing tolerances of 5 micron precision to a 10 micron target are required. After main amplification the beams are shortened by up to 1,000x in time in the ARC compressor vessel and aimed at backlighter targets in the NIF target chamber. Alignment Stability and Verification of the compressor gratings is critical to ensuring the ARC pulses meet their experimental specifications.
	Poster THPPC141 [4.485 MB]