Table 1. Statistics of X-ray and laser photons corresponding to the spectra shown in Figs. 3 and 5.

	Pump-sequential-probes	Pump-flow-probe
Incident flux (ph/s)	6.5*1012	4*1011
Total number of fluorescent photons/s	7*109	3*108
Total counts/s of the detector	1.9*107	6*105
Total counts/s of the detector for each time point	2.9*103	6*105
Counts/s for selected energy ROI	--	1.2*105
Detected fluorescent counts/s	2*103	4.8*104
Neff Effective number of counts/s	1.4*103	2*104
Parameters of accumulation	4 s/point 40 spectra 60 points	30s/point 20 spectra 30 points
Total dose of laser radiation (photons)	1.3*1022	4*1022
Total X-ray dose (photons)	6.2*1016	1.4*1016
Accumulated effective “laser on” X-ray counts/point	2.2*105	1.2*107
Expected Noise of the difference signal normalized to the absorption edge jump	3.3*10−3	5.6*10−4
Observed noise (Average error above the edge)	5*10−3	5.4*10−4