The project is divided into several work-packages, addressing targeting key events affecting the inner-core Fe-alloy and leading to observations of the inner-core as we can see it today. Understanding the physical characteristics of metals under extreme pressure and temperature conditions is at the heart of all three, working either on iron-alloys themselves, or other metal analogues to constrain our physical models.
A new class of experiments at the European XFEL, capable of producing ultrashort and extremely intense X-ray flashes at a rate of 27,000 times per second, is the basis for the project's first package. The facility is coupled with static high pressure devices, such as diamond anvil cells, to reach the conditions of the Earth’s inner core. It is also used in conjunction with an intense optical laser, Dipole-100X, to produce temporally shaped pulses and shock waves into our samples. These allow to test and explore the physical properties of iron and iron alloys in conditions that could not be reached previously, which we are currently testing and exploring in the framework of the project.
These experiments are complimented with laboratory and synchrotron-based experiments addressing finer questions regarding iron alloys in the Earth inner-core. In particular, we wish to understand how the iron alloy can affect geophysical observables such as seismic wave velocities and anisotropy, seismic attenuation, and visco-elastic relaxation. To do so, we are in the process of developing new devices to work at conditions relevant to the Earth’s inner core. One route relies on experiments high temperature, close to melting, on metal analogues to develop physical models to be used in extrapolations. The other route uses combined conditions of pressures and temperatures. This work is ongoing and will be described more thoroughly as the project moves forward.
