(a) A schematic diagram of the first version of the cell, taken from Agostini et al. (2018). (b) A drawing of the cell and (c) a photograph of the cell from above, with the fluorescence sample holder. The cell has two windows in the path of the X-ray beam for transmission measurements. A third window on one side allows the fluorescence to leave the cell. In fluorescence measurements, the sample is placed in a holder at 45° with respect to the incoming and outgoing X-ray beams. Additionally, the cell is equipped with pipes for gases (in and out) and internal heating.