Coded aperture x-ray imaging of high power laser-plasma interactions on the Vulcan Laser System

In this paper we demonstrate the implementation of a modified uniformly redundant array (MURA) coded aperture in the x-ray imaging of high power laser produced plasma. We detail the process of design and manufacture of a self-supporting tantalum coded aperture with ~ 50% open area to work in the 1-25 keV x-ray regime. The advantage of using a coded aperture imaging system in this high noise environment in comparison to a standard pinhole aperture is its larger solid angle and increased signal to noise. The increased solid angle allows the aperture and detector to be placed at a further distance from the interaction point. This is beneficial as it reduces the mechanics in the close proximity of the often crowded interaction region and moves the detector which can include sensitive electronics further away from the source of EMP, hard x-rays and secondary sources generated in the interaction. Here we present initial data taken on an experiment using the Vulcan Petawatt Laser at the Central Laser Facility of a prototype x-ray imager.