New Optical Diagnostics for Equation-of-State Experiments on the Janus Laser

Dylan Spaulding, University of California, Berkeley

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We report on the first implementation of both a streaked optical pyrometer (SOP) and nanosecond broadband reflectometry diagnostic for observation of ~Mbar laser-driven dynamic compression experiments on the Janus laser at Lawrence Livermore National Laboratory. Temporally and spatially resolved optical pyrometry has been performed in the visible spectrum to measure self-emission from the sample in parallel with velocimetry and reflectivity measurements. A variety of target materials have been investigated under both ramp-compression (ICE) and shock-loading conditions with absolute temperatures obtained via a greybody comparison. Furthermore, a nanosecond, time-resolved, broadband reflectivity diagnostic has been successfully demonstrated and is being developed for permanent use in combination with pyrometry for equation-of-state measurements. Results from both diagnostics are discussed for materials including SiO2 , diamond, MgSiO3 and MgO.

This work was performed under the auspices of the U.S. DOE by LLNL under Contract No. W-7405-ENG-48.

Abstract Author(s): Dylan K. Spaulding (1), Damien G. Hicks (2), Raymond F. Smith (2), Jon H. Eggert (2), R. Stewart McWilliams (1,2), Gilbert W. Collins (2), Raymond Jeanloz (2)<br />1&nbsp; Department of Earth and Planetary Science, University of California, Berkeley, CA, 94720<br />2&nbsp; V-Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550