Time Lens Photon Doppler Velocimetry (TL-PDV) for extreme measurements

Area of Science:

• Shock physics
• Optical velocimetry
• Inertial confinement fusion (ICF) diagnostics

Background:

• Conventional photon Doppler velocimetry (PDV) systems struggle to capture extreme surface velocities (>50 km/s) required for shock physics and ICF.
• Recent advancements in ICF necessitate velocimetry techniques capable of measuring velocities exceeding 100 km/s.

Purpose of the Study:

• To experimentally demonstrate and validate Time lens PDV (TL-PDV) for high-velocity measurements.
• To assess the performance and accuracy of TL-PDV over an extended velocity range.
• To establish TL-PDV as a viable diagnostic for extreme condition material characterization.

Main Methods:

• Utilizing a time lens to periodically magnify the high-frequency beat signal from a conventional PDV system in the optical domain.
• Experimentally validating TL-PDV performance over a 74 km/s velocity range.
• Comparing TL-PDV results with conventional PDV in laser-driven micro-flyer experiments.

Main Results:

• Successful experimental demonstration of TL-PDV for the first time.
• Validation of TL-PDV performance with high accuracy over a 74 km/s velocity range.
• Excellent agreement between TL-PDV and conventional PDV measurements in micro-flyer experiments.

Conclusions:

• TL-PDV offers the largest velocity dynamic range currently available for PDV systems.
• The technique is scalable to even higher velocities, making it suitable for extreme conditions.
• TL-PDV is an ideal candidate for material characterization, particularly for optimizing ICF experiments.