A high spatio-temporal resolution optical pyrometer at the ORION laser facility.

Area of Science:

• Physics
• Materials Science

Background:

• Accurate temperature measurement of small, heated targets is crucial for understanding warm dense matter.
• Existing diagnostics often lack the required spatial and temporal resolution for such measurements.

Purpose of the Study:

• To design and calibrate a streaked pyrometer for measuring the temperature of ≈100 μm diameter heated targets in the warm dense matter region.
• To achieve picosecond time resolution and high spatial resolution for detailed analysis.

Main Methods:

• Utilized an f/1.4 objective and a minimal optical relay system for high light collection efficiency.
• Employed a highly sensitive Axis Photonique streak camera with a P820PSU streak tube.
• Performed absolute calibration of two streak cameras over 8 spectral bands (425–650 nm) using a picosecond white light source.

Main Results:

• Achieved picosecond time resolution and 1 μm spatial resolution.
• Demonstrated capability to measure thermal emission from targets at temperatures as low as 1 eV.
• Obtained absolute calibration data, showing camera response variation between 47 ± 8 and 14 ± 4 photons/count.

Conclusions:

• The calibrated streaked pyrometer enables accurate absolute and color temperature measurements in warm dense matter.
• The diagnostic's high sensitivity and resolution advance the study of extreme material states.