A hydrothermal apparatus for X-ray absorption spectroscopy of hydrothermal fluids at DESY

Klemme S, Feldhaus M, Potapkin V, Wilke M, Borchert M, Louvel M, Loges A, Rohrbach A, Weitkamp P, Welter E, Kokh M, Schmidt C, Testemale D

Abstract

We present a new autoclave, which enables in-situ characterization of hydrothermal fluids at high pressures and high temperatures at synchrotron X-ray radiation sources. The autoclave has been specifically designed to enable X-ray absorption spectroscopy in fluids with applications to mineral solubility and element speciation analysis in hydrothermal fluids in complex compositions. However, other applications such as Raman spectroscopy in high-pressure fluids are also possible with the autoclave. First experiments were run at pressures between 100 and 600 bars, and at temperatures between 25°C and 550°C, and preliminary results on scheelite dissolution in fluids of different compositions show that the autoclave is well suited to study the behavior of ore-forming metals at P-T conditions relevant to the Earth's crust.