Raman X-ray spectroscopy of photo-dissociation of standard alcohol medium for high pressure experiments under x-ray irradiation

The intense x-rays available at EBS-ESRF are known to be able to trigger undesired effects, such as chemical modifications in radiation sensitive materials. Recently, we have observed the chemical dissociation of the alcohol solution used as pressure transmitting medium in high-pressure experiments. The reaction is complex, involving the production of liquid hydrogen and solidification of solids of unknown stoichiometry. To determine the nature of the different products of this speciation as a function of pressure, we propose to perform X-Ray Raman Spectroscopy in-situ within Diamond Anvil Cell, as this is the only technic allowing us to probe the absorption edges of low-z elements under pressure. A successful experiment will lead to the determination of the nature of the modified pressure transmitting elements as a function of dose and pressure, providing a comprehensive base for the high-pressure community to design experiments and avoid undesired sample-environment interactions.