Abstract
In conventional gases and plasmas, the coefficient of thermal conduction is given by Spitzer's theory, which assumes that heat fluxes are proportional to temperature gradients. However, experimental work which recreated astrophysical conditions at the Laboratory for Laser Energetics' (LLE) OMEGA and Lawrence Livermore National Laboratory's National Ignition Facility (NIF) demonstrated that the presence of turbulent-dynamo-amplified magnetic fields in large magnetic Prandtl number regimes lead to an observed reduction of heat transport by at least two orders of magnitude. This effect was inferred using line-integrated X-ray emission diagnostics. This work presents new optical Thomson scattering data where time-resolved ion acoustic wave (IAW) and electron plasma wave (EPW) scattering was performed on NIF and OMEGA. Thomson scattering provides detailed information on the small-scale plasma conditions, improving the accuracy of line-integrated X-ray emission analysis. In addition, the autocorrelation analysis of the Thomson scattering data can yield information on relevant transport properties, such as thermal diffusion, furthering understanding of the mechanisms that give rise to the suppression of heat conduction.
*This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award No. DE-NA0003856, the University of Rochester, and the New York State Energy Research and Development Authority. The research leading to these results also received funding from the U.K. EPSRC (grant numbers EP/M022331/1 and EP/N014472/1); the European Research Council under the European Community's Seventh Framework Programme (FP7/2007-2013)/ERC grant agreements nos. 256973 and 247039; the U.S. DOE under Contract No. B591485 to LLNL. We acknowledge support by the U.S. DOE NNSA under Awards DE-NA0002724, DE-NA0003605, DE-NA0003842, DE-NA0003934, DE-NA0003856, and Subcontracts 536203 and 630138 with LANL and B632670 with LLNL; the NSF under Award PHY-2033925; and the U.S. DOE Office of Science Fusion Energy Sciences under Award DE-SC0021990.
