Monochromatic X-ray propagation in multi-Z media for imaging and diagnostics including K$_{\alpha}$ Resonance Fluorescence

Aimed at monochromatic X-ray imaging and therapy [1], broadband, monochromatic, and quasi-monochromatic X-ray sources and propagation through low and high-Z (HZ) media were studied with numerically and experimentally. Monte Carlo simulations were performed using the software package Geant4, and a new code Photx, to simulate X-ray image contrast, depth of penetration, and total attenuation. The data show that monochromatic and quasi-monochromatic X-rays achieve improved contrast at lower absorbed radiation doses compared to conventional broadband 120 kV or CT scans. Experimental quasi-monochromatic high-intensity laser-produced plasma sources and monochromatic synchrotron beam data are compared. Physical processes responsible for X-ray photoexcitation and absorption are numerically modelled, including a novel mechanism for accelerating K$_{\alpha}$ resonance fluorescence via twin monochromatic X-ray beam [2]. Potential applications are medical diagnostics and high-Z material detection.\\ 1. S.N.Lim, et al, JRR 56, 77 (2015)\\ 2. S.N.Nahar, A.K. Pradhan, JQSRT 155, 32 (2015)\\ Acknowledgement: Ohio Supercomputer Center, Columbus, OH