Combining x-ray K${\beta_{1,3}}$, valence-to-core, and X-ray Raman spectroscopy for studying Earth materials at high pressure and temperature

X-ray emission and x-ray Raman scattering spectroscopy are powerful tools to investigate the local electronic and atomic structure of high and low Z elements in-situ. Notably, these methods can be applied for in-situ spectroscopy at high pressure and high temperature using resistively or laser-heated diamond anvil cells in order to achieve thermodynamic conditions which are present in the Earth's interior. We developed a setup for combined x-ray emission and x-ray Raman scattering studies at beamline P01 of PETRA III using a portable wavelength-dispersive von Hamos spectrometer together with the permanently installed multiple-analyzer Johann-type spectrometer. The capabilities of this setup discussed through the investigation of are exemplified by investigating the iron spin crossover of siderite FeCO$_3$ up to $49.3 \, \text{GPa}$ by measuring the Fe M$_{2,3}$-edge and Fe K$\beta_{1,3}$ emission line simultaneously. With this setup, the Fe valence-to-core emission can be detected simultaneously with the K$\beta_{1,3}$ emission line providing complementary information on the sample's electronic structure. By implementing a laser-heating device, we demonstrate the strength of using a von Hamos type spectrometer for spin state mapping at extreme conditions. Finally, we give different examples of low Z elements' absorption edges relevant for application in geoscience that are accessible with the Johann-type XRS spectrometer. This setup provides a unique combination to gain new insights of the spin transition and compression mechanisms of Earth's mantle materials of importance for comprehension of the macroscopic physical and chemical properties of the Earth's interior.