Kirkpatrick-Baez microscope for hard X-ray imaging of fast ignition experiments

Area of Science:

• Plasma Physics
• X-ray Optics
• Laser Fusion

Background:

• Traditional Bragg crystal imagers have limitations in bandwidth for Fast Ignition experiments.
• Imaging Kα emission from tracer layers is crucial for understanding plasma dynamics.

Purpose of the Study:

• To develop a broadband X-ray microscope as an alternative to narrow-band imagers.
• To enhance diagnostic capabilities for Fast Ignition experiments at the Titan laser facility.

Main Methods:

• Development of a Kirkpatrick-Baez X-ray microscope with a re-entrant design for external alignment.
• Utilizing platinum-coated mirrors operating at a 0.5° grazing incident angle.
• Employing superpolished substrates with sub-Angstrom roughness for high-resolution imaging.

Main Results:

• Achieved an experimental resolution of 15 μm at the center of the field of view.
• Demonstrated a broad spectral window (4–9 keV) for simultaneous observation of multiple spectral regions.
• The design allows for live indication of alignment and incident angle via unfiltered and reflected signals.

Conclusions:

• The developed Kirkpatrick-Baez X-ray microscope provides a viable broadband alternative for Kα emission imaging in Fast Ignition.
• Its high resolution and broad spectral coverage offer significant advantages for diagnosing complex targets.
• The unique real-time alignment feedback enhances experimental efficiency and data reliability.