Quantifying equation-of-state and opacity errors using integrated supersonic diffusive radiation flow experiments on the National Ignition Facility

• Published in: Physics of plasmas 2015-04, Vol.22 (4)
• Main Authors: Guymer, T. M., Moore, A. S., Morton, J., Allan, S., Bazin, N., Benstead, J., Bentley, C., Comley, A. J., Garbett, W., Reed, L., Stevenson, R. M., Kline, J. L., Cowan, J., Flippo, K., Hamilton, C., Lanier, N. E., Mussack, K., Obrey, K., Schmidt, D. W., Taccetti, J. M.
• Format: Article
• Language: English
• Subjects: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; COMPUTERIZED SIMULATION; DENSITY; DIFFUSION; EQUATIONS OF STATE; ERRORS; EXPERIMENTAL DATA; FOAMS; HYPOTHESIS; LASER RADIATION; OPACITY; RADIATION TRANSPORT; SUPERSONIC FLOW; US NATIONAL IGNITION FACILITY
• ISSN: 1070-664X; 1089-7674
• DOI: 10.1063/1.4919025

A well diagnosed campaign of supersonic, diffusive radiation flow experiments has been fielded on the National Ignition Facility. These experiments have used the accurate measurements of delivered laser energy and foam density to enable an investigation into SESAME's tabulated equation-of-state values and CASSANDRA's predicted opacity values for the low-density C{sub 8}H{sub 7}Cl foam used throughout the campaign. We report that the results from initial simulations under-predicted the arrival time of the radiation wave through the foam by ≈22%. A simulation study was conducted that artificially scaled the equation-of-state and opacity with the intended aim of quantifying the systematic offsets in both CASSANDRA and SESAME. Two separate hypotheses which describe these errors have been tested using the entire ensemble of data, with one being supported by these data.