Quantitative Flash X-ray Imaging of Liquid Mass Distribution in Optically Dense Sprays

The scattering of visible light in optically dense sprays compromises the ability of common spray imaging techniques to capture the quantitative liquid mass distribution. Because of reduced susceptibility to multiple scattering, X-ray radiography can overcome the difficulties associated with optical wavelengths and provide quantitative measurements of liquid mass distribution in a variety of sprays. In the current work, we investigate the conditions under which broadband X-ray radiation from compact tube sources can be used to achieve similar accuracy to the narrowband, high-intensity, soft X-ray source at the Advanced Photon Source (APS) at Argonne National Laboratory. Radiography is used 2-D imaging of sprays with different liquid path lengths to evaluate the effects of energy dependent X-ray attenuation, or so-called beam hardening. We present 2-D imaging data using a time-resolved flash X-ray source. These measurements are compared with data acquired using the APS for the same spray conditions. The results indicate that quantitative images can be achieved using broadband X-ray sources, although the imaging system should be optimized to balance X-ray bandwidth, signal-to-noise ratio, sensitivity, spatial resolution, and temporal resolution. * Corresponding author: [email protected]