Multi-frame, ultrafast, x-ray microscope for imaging shockwave dynamics

Area of Science:

• Plasma Physics
• Materials Science
• Fusion Energy Research

Background:

• Defects like micro-voids in inertial confinement fusion (ICF) fuel capsule ablators impede progress toward clean energy.
• Understanding the interaction between laser-driven shock waves and these micro-voids is critical for ICF performance.

Purpose of the Study:

• To investigate the effects of micro-voids on shock wave propagation and material compression within ICF fuel capsules.
• To benchmark material performance and understand microstructural evolution in the presence of defects.

Main Methods:

• Utilized the Matter in Extreme Conditions (MEC) instrument at the Linac Coherent Light Source (LCLS) with ultrafast x-ray imaging (UXI).
• Employed principal component analysis (PCA) and image alignment for image correction, and a transport-of-intensity (TIE) based method for areal density measurement.
• Generated phase and attenuation maps using a 2D hydrodynamic radiation code (xRAGE) for comparison with experimental data.

Main Results:

• Successfully imaged shock wave interactions with micro-voids in ICF fuel capsules.
• Quantified the average projected mass density (areal density) of experimental images.
• Provided a benchmark for material performance by comparing simulated and experimental XPCI images.

Conclusions:

• Micro-voids significantly alter shock wave propagation and material compression dynamics in ICF fuel capsules.
• The developed imaging and analysis techniques offer crucial insights into defect behavior on ICF-relevant timescales.
• This research advances the understanding necessary for developing more robust and efficient ICF energy systems.