X-ray spectroscopy of extreme states of matter created by petawatt-laser-driven nanostructured arrays

The direct coupling of energy from an optical laser to a near-solid-density plasma is limited due to
negligible penetration depths of light beyond the critical density of a material, making it difficult to
create homogeneous, dense, high-energy-density systems. However, by tailoring the surface
properties of materials at the nanoscale - in particular by producing nano-structured targets
composed of oriented, anisotropic nano-wires - novel samples can be developed with substantially
different optical properties. Such nano-wires have recently been shown capable of strongly
enhancing the coupling of matter with optical light, yielding absorptions exceeding 95%, and large
penetration depths in metallic samples.
This project will focus on investigating the interaction of light with such nano-structured targets, and
will study their behaviour when interacting with large-scale PW laser systems. These systems
show promise as a new way to access matter in conditions relevant to astrophysical and inertial
confinement fusion research, but also show potential as a novel source of bright laser-driven X-ray
and particle beams. A range of experimental diagnostics including X-ray emission spectroscopy will
be employed, and coupled with computational tools based on non-LTE atomic kinetics simulations.
This project is part-funded by OxCHEDS and is run in close collaboration with AWE. This project
falls within the EPSRC research areas of Plasma and lasers, and Light matter interaction and
optical phenomena.