Structure of Geological Fluids

Aqueous ionic solutions under high pressure (P) and temperature (T) conditions form a class of geological fluids that are of fundamental importance for understanding many of the geophysical processes that take place within planet Earth. A prerequisite for developing realistic atomistic and thermodynamic models of these liquids is detailed knowledge about their structures. For example, it is necessary to know the speciation (type and quantity of the different ionic configurations) at high P and T in order to understand equilibrium processes and the way in which these processes are perturbed by e.g. the addition of CO2, an important issue in sequestering green-house gas.


The overall aim of this PhD project is to solve the structure of several geological fluids by using the powerful method of neutron diffraction with isotope substitution to measure the coordination environment of selected ions in solution. The diffraction experiments will be made under extreme high-pressure and high-temperature conditions. Part of the experimental setup, involving the Paris-Edinburgh press, has already been developed and tested for neutron diffraction experiments. The other part of the setup will require the development of apparatus to cover a lower pressure but higher temperature range. There may also be the possibility for investigating the dynamical properties of geological fluids by using inelastic neutron scattering. All of the experimental results will be used to inform the development of appropriate molecular dynamics models.

The PhD project will be located in Grenoble (France), at the ILL, and at the University of Bath.

An international team of experts, including Prof. Philip Salmon (Bath), Dr Anita Zeidler (Bath), Prof. Stefan Klotz (Paris) and Dr Henry Fischer (ILL), will supervise the work of the PhD student.