Transport properties at the extreme: opportunities for HED

Mohamed Zaghoo

Monday, November 2, 2020

The study of transport phenomena in dense matter is a canonical problem in physical and astrophysical sciences. These phenomena encompass all forms of micro and macrophysical changes related to the dissipative flow of charge, mass, energy and momentum, and describe processes that range from accretion in protoplanetary disks, giant impacts, Earth’s water or carbon cycles, to growth of hydrodynamic instabilities, ablation or inertial confinement fusion. Yet despite their importance, these transport coefficients remain some of the least well-constrained physical parameters. This is even more palpable for newly discovered extrasolar planets. This presents a formidable opportunity for High-energy density science to inform of the geophysical and chemical processes inside these astrophysical bodies. In this talk, I shall discuss two examples of how new advances in high-pressure experiments are providing key data on the dynamo process and thermodynamic states of gas-giant and terrestrial-like planets. In the first example, I show that recent experiments on dense fluid hydrogen conductivity suggests a shallower origin for Jupiter’s magnetic effects, consistent with new data from Juno. In the second example, I focus on the thermomechanical behavior of dense iron and mantle silicates at conditions characteristic of super-Earths. I show that Earth-like planets with more than 2-3 Earth masses might lack a convecting liquid cores, inhibiting dynamo action in these planets, and likely implicating their potential habitability.


Meeting ID: 951 8439 8045

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