Imaging scattered x-ray radiation for measurement of local electron density in high-energy-density experiments

Abstract

Imaging high-energy-density systems with scattered x-ray photons has several unique characteristics that differentiate it from the transmission radiography methods that have traditionally been used to diagnose these experiments. Because x-ray photons scatter primarily from the plasma electrons, the degree of scattering from any point in a target is roughly proportional to the electron density at that point. By constraining the directions of incident and scattered photons, the scattering event can be localized, resulting in a point-wise, internal map of the target electron density. Additionally, a scattering experiment is not restricted to the collinear source-target-detector geometry of transmission radiography. This flexibility allows for multiple detectors to image light from a single source, though potentially at different scattering angles or energy bands. Presented in this paper is the theoretical underpinning for scattered x-ray imaging, as well as a description of an upcoming proof-of-principle experiment to be conducted at the OMEGA Laser Facility.