Tracking chemical reaction using soft-X-Ray absorption spectroscopy with a table-top water-window X-ray source

We demonstrate femtosecond time-resolved soft-X-ray absorption spectroscopy of liquid samples by combining a sub-micrometer-thin flat liquid jet with a high-harmonic table-top source covering the entire water-window range (284 - 538 eV). Our measurements temporally resolve the gradual appearance of absorption features below the carbon K-edge of ethanol and methanol during strong-field ionization, which trace the valence-shell ionization dynamics of the liquid alcohols with a temporal resolution of similar to 30 fs.