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Uncovering signatures of preheat performance in MagLIF experiments using stimulated Raman and Brillouin backscatter spectra

Fein, Jeffrey R.; Bliss, David E.; Geissel, Matthias G.; Harvey-Thompson, Adam J.; Awe, Thomas J.; Ampleford, David A.; Glinsky, Michael E.; Laros, James H.; Harding, Eric H.; Macrunnels, K.A.; Patel, Sonal P.; Ruiz, Daniel E.; Scoglietti, Daniel S.; Smith, Ian C.; Weis, Matthew R.; Peterson, Kara J.

Abstract not provided.

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TYPE Conference Poster YEAR 2018
OSTI

Pushing Laser Pre-Heat in MagLIF

Geissel, Matthias G.; Harvey-Thompson, Adam J.; Fein, Jeffrey R.; Woodbury, Daniel W.; Davis, Daniel R.; Bliss, David E.; Scoglietti, Daniel S.; Gomez, Matthew R.; Ampleford, David A.; Awe, Thomas J.; Colombo, Anthony P.; Weis, Matthew R.; Jennings, Christopher A.; Glinsky, Michael E.; Slutz, Stephen A.; Ruiz, Daniel E.; Peterson, Kyle J.; Smith, Ian C.; Shores, Jonathon S.; Kimmel, Mark W.; Rambo, Patrick K.; Schwarz, Jens S.; Galloway, B.R.; Speas, Christopher S.; Porter, John L.

Abstract not provided.

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TYPE Conference Poster YEAR 2018
OSTI

Measurements of Z Electrode Temperatures Using Absolutely Calibrated Streaked Visible Spectroscopy Systems and Avalanche Photodiodes

IEEE International Conference on Plasma Science

Patel, Sonal P.; Johnston, Mark D.; Bliss, David E.; Laity, George R.; Gomez, Matthew R.; Falcon, Ross E.; Scoglietti, Daniel S.; Macrunnels, K.A.; Savage, Mark E.; Cuneo, M.E.

Absolute calibration of streaked visible spectroscopy systems has been performed at Z-machine at Sandia National Labs in order to determine temperatures of electrode surfaces during the current pulse. The ability to calibrate the full system, including all fiber optic runs and probes is crucial to understanding errors in the calibration process. The calibration procedure involves imaging a blackbody light source, with a known spectral radiance which is coupled to an integrating sphere. This source is streaked slowly over a few ns using Sydor streak cameras. The slow sweep is converted to a 100-500ns sweep by imaging a bright light source on both sweep rates, and obtaining wavelength and time dependent correction curves. Any broadband light source or several laser lines of differing wavelengths can be used for this correction. This technique has yielded temperature estimates of several eV in the Z convolute.

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TYPE Conference Poster YEAR 2018
OSTIScopus

Nonlinear Laser-Plasma Interaction in Magnetized Liner Inertial Fusion

Proceedings of SPIE - The International Society for Optical Engineering

Geissel, Matthias G.; Awe, Thomas J.; Bliss, David E.; Campbell, Edward M.; Gomez, Matthew R.; Harding, Eric H.; Harvey-Thompson, Adam J.; Hansen, Stephanie B.; Jennings, Christopher A.; Kimmel, Mark W.; Knapp, Patrick K.; Lewis, Sean M.; McBride, Ryan D.; Peterson, Kyle J.; Schollmeier, Marius; Scoglietti, Daniel S.; Sefkow, Adam B.; Shores, Jonathon S.; Sinars, Daniel S.; Slutz, Stephen A.; Smith, Ian C.; Speas, Christopher S.; Vesey, Roger A.; Porter, John L.

Sandia National Laboratories is pursuing a variation of Magneto-Inertial Fusion called Magnetized Liner Inertial Fusion, or MagLIF. The MagLIF approach requires magnetization of the deuterium fuel, which is accomplished by an initial external B-Field and laser-driven pre-heat. Although magnetization is crucial to the concept, it is challenging to couple sufficient energy to the fuel, since laser-plasma instabilities exist, and a compromise between laser spot size, laser entrance window thickness, and fuel density must be found. Ultimately, nonlinear processes in laser plasma interaction, or laser-plasma instabilities (LPI), complicate the deposition of laser energy by enhanced absorption, backscatter, filamentation and beam-spray. We determine and discuss key LPI processes and mitigation methods. Results with and without improvement measures are presented.

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TYPE Journal Article YEAR 2016
DOIOSTI

Pure-Rotational fs/ps CARS measurements of temperature and concentration using a second-harmonic bandwidth-compressed probe

52nd AIAA Aerospace Sciences Meeting - AIAA Science and Technology Forum and Exposition, SciTech 2014

Kearney, Sean P.; Scoglietti, Daniel S.

A hybrid fs/ps pure-rotational CARS scheme is demonstrated in the product gases of premixed hydrogren/air and ethylene/air flat flames. Near-transform-limited, broadband femtosecond pump and Stokes pulses impulsively prepare a rotational Raman coherence, which is later probed by a high-energy, frequency-narrow picosecond pulse, generated by sum-frequency mixing of linearly chirped broadband pulses with conjugate temporal phase. Spectral fitting is demonstrated for both shot-averaged and single-laser-shot spectra. Measurement accuracy is quantified by comparison to adiabatic-equilibrium calculations for the hydrogen/air flames, and by comparison to nanosecond CARS measurements for the ethylene/air flames. Temperature-measurement precision is 1-3% and O2/N2 precision is 2-10% based on histograms constructed from 1000 single-shot measurements acquired at a data rate of 1 kHz. These results indicate that hybrid fs/ps rotational CARS is a quantitative tool for kHz-rate combustion temperature/species data.

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TYPE Conference YEAR 2014
ScopusOSTIDOI
19 Results
19 Results