“…More recently, X-ray fluorescence experiments have been performed to obtain quantitative measurements of density fields in turbulent shear-coaxial jet flames [13], sampling-probe perturbations [14], and heated miniature reactors [15], demonstrating the feasibility of using krypton and argon as fluorescent species. Laboratory X-ray sources have been employed for tomographic imaging of in-situ combustion for oil recovery [16], for probing the spray structure in a full-cone atomizer [17], for investigating the scalar mixing in turbulent jets [18], and for examining the interstitial flame structure and temperature field in porous media burners [19].…”