Identifying, quantifying, and mitigating background with the time-resolved x-ray diffraction platform at the National Ignition Facility.

The time-resolved x-ray diffraction platform at the National Ignition Facility (NIF) fields electronic sensors closer to the exploding laser-driven target than any other NIF diagnostic in order to directly detect diffracted x rays from highly compressed materials. We document strategies to characterize and mitigate the unacceptably high background signals observed in this geometry. We specifically assess the possible effects of electromagnetic pulse, x-ray fluorescence, hot electrons, and sensor-specific non-x-ray artifacts.

Time resolved x-ray diffraction using the flexible imaging diffraction diagnostic for laser experiments (FIDDLE) at the National Ignition Facility (NIF): Preliminary assessment of diffraction precision.

The Flexible Imaging Diffraction Diagnostic for Laser Experiments (FIDDLE) is a new diagnostic at the National Ignition Facility (NIF) designed to observe in situ solid-solid phase changes at high pressures using time resolved x-ray diffraction. FIDDLE currently incorporates five Icarus ultrafast x-ray imager sensors that take 2 ns snapshots and can be tuned to collect X-rays for tens of ns. The platform utilizes the laser power at NIF for both the laser drive and the generation of 10 keV X-rays for ∼10 ns using a Ge backlighter foil.

Developing time-resolved x-ray diffraction diagnostics at the National Ignition Facility (invited).

As part of a program to measure phase transition timescales in materials under dynamic compression, we have designed new x-ray imaging diagnostics to record multiple x-ray diffraction measurements during a single laser-driven experiment. Our design places several ns-gated hybrid CMOS (hCMOS) sensors within a few cm of a laser-driven target. The sensors must be protected from an extremely harsh environment, including debris, electromagnetic pulses, and unconverted laser light.

Electrical design of the flexible imaging diffraction diagnostic for laser experiments (FIDDLE) at the National Ignition Facility (NIF)-Requirements, design, and performance.

The Flexible Imaging Diffraction Diagnostic for Laser Experiments (FIDDLE) is a newly developed diagnostic for imaging time resolved diffraction in experiments at the National Ignition Facility (NIF). It builds on the successes of its predecessor, the Gated Diffraction Development Diagnostic (G3D). The FIDDLE was designed to support eight Daedalus version 2 sensors (six more hCMOS sensors than any other hCMOS-based diagnostic in NIF to date) and an integrated streak camera.

A MHz X-ray diffraction set-up for dynamic compression experiments in the diamond anvil cell.

An experimental platform for dynamic diamond anvil cell (dDAC) research has been developed at the High Energy Density (HED) Instrument at the European X-ray Free Electron Laser (European XFEL). Advantage was taken of the high repetition rate of the European XFEL (up to 4.5 MHz) to collect pulse-resolved MHz X-ray diffraction data from samples as they are dynamically compressed at intermediate strain rates (≤10 s), where up to 352 diffraction images can be collected from a single pulse train.