Internship and thesis proposals
Sound velocity measurements in methane under extreme pressure and temperature conditions: validity of Birch's law for planetary interiors

Domaines
Condensed matter

Type of internship
Expérimental
Description
Methane (CH₄) is a major component of the ice layers present in giant planets such as Uranus and Neptune. Understanding its behavior under extreme pressure and temperature conditions is crucial for refining models of the interiors of these planets. Specifically, the equation of state (P, V, T) of methane is key information. However, current data is limited and does not cover the pressure and temperature ranges representative of planetary interiors. The goal of this internship is to explore the phase diagram of fluid methane using Brillouin and Raman spectroscopy techniques. We will determine the stability domain of the CH₄ molecule and the conditions under which it dissociates into carbon (graphite or diamond) and hydrogen. Furthermore, it has been shown that at 300 K, the speed of sound in methane varies linearly with density, in accordance with Birch’s law. The internship aims to extend these measurements to high temperatures in order to track the evolution of methane’s thermodynamic properties in the fluid phase. The data obtained will contribute to refining the planetary interior models of Uranus and Neptune and are expected to be published in an international scientific journal.

Contact
Gunnar Weck
Laboratory : Laboratoire Matière en Conditions Extrêmes (LMCE) - ...
Team : Hautes pressions statiques
Team Website
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