MR13C-2723
Searching for the Hydrogen Plasma Phase Transition on the National Ignition Facility

Monday, 14 December 2015
Poster Hall (Moscone South)
Marius A Millot1, Gilbert Wilson Collins1, Raymond Jeanloz2, Russell J Hemley3, Alexander F Goncharov4, Paul Loubeyre5, Stephanie Brygoo5, Ryan Stewart McWilliams6, Peter M Celliers1, Jon Eggert1, J. Ryan Rygg1, Sebastien Le Pape1, Dayne Fratanduono1, Sebastien Hamel1, Luc Peterson1, Nathan Meezan1 and David Braun1, (1)Lawrence Livermore National Laboratory, Livermore, CA, United States, (2)University of California Berkeley, Berkeley, CA, United States, (3)Carnegie Inst. of Washington, Washington, DC, United States, (4)Carnegie Institution for Science Washington, Washington, DC, United States, (5)CEA Commissariat à l'Energie Atomique DAM, Arpajon Cedex, France, (6)School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
Abstract:
New dynamic-compression techniques allow scientists to recreate the material states expected to exist in the deep interiors of planets, including the newly discovered extra solar planets. 

At the conditions existing deep inside stars and planets, pressure produces highly degenerate conditions (strong quantum effects), with atoms brought closer than the Bohr radius. State-of-the-art calculations indicate that such strong degeneracy effects induce the insulator-conductor transition in fluid hydrogen to become first-order, i.e. discontinuous, at temperatures below about 2500 K. This phase transition is called the Plasma Phase Transition (PPT). This problem challenges the most advanced simulations and theories resulting in a span of proposed conditions for the PPT from 1 to 5 Mbar, between 1000 and 2500 K. At higher temperature the metallization onset is thought to be continuous. 

We will present recent experiments using a reverberation compression scheme on the National Ignition Facility to compress cryogenic deuterium up to several megabars (1Mbar=100 GPa) while keeping the temperature much lower than using single shock compression.

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