Characterization of Flash X-Ray Source From a Marx-Based Pulse Power System

Abstract

The source characterization of a Flash X-ray (FXR) device is essential in defining its utility for dynamic radiography. A Marx generator [550 kV, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$50~\Omega $ </tex-math></inline-formula> , and 45 ns full-width half-maxima (FWHM)] based FXR source operating in the voltage range 200–550 kV has been characterized. The FXR electron beam diode has a cylindrical geometry with stainless steel (SS) knife-edge cathode and tapered tip Tungsten rod as anode. The FXR source is connected to the Marx generator-based pulsed power system using a flexible high-voltage cable feed through. The hard X-ray spectrum was measured using a differential absorption spectrometer (DAS). The FWHM of the spot size of FXR source was measured using a pinhole camera and was estimated to lie between 1.83 and 2.31 mm. The on-axis dose measured at 1 m matches well with the calculated dose <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$D \alpha V^{2.2}I\Delta t$ </tex-math></inline-formula> , where <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$V$ </tex-math></inline-formula> is the applied voltage and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$I$ </tex-math></inline-formula> is the current, and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Delta t$ </tex-math></inline-formula> the time duration.