Atmospheric effects on the laser-driven avalanche-based remote detection of radiation

Area of Science:

• Physics
• Optical Engineering
• Environmental Science

Background:

• Laser-induced avalanche breakdown is a key technology for remote sensing.
• Atmospheric conditions like turbulence and aerosols can significantly affect laser propagation and detection.
• Understanding these effects is crucial for reliable remote detection of radioactive materials.

Purpose of the Study:

• To investigate the impact of realistic atmospheric conditions on laser-induced avalanche breakdown.
• To evaluate the feasibility of mid-IR and long-wave-IR lasers for remote radioactive material detection under various atmospheric scenarios.
• To validate propagation simulations with experimental data.

Main Methods:

• Experimental measurements of mid-IR laser-induced avalanche breakdown in controlled turbulence.
• Simulations of laser propagation through atmospheric turbulence for both mid-IR and long-wave-IR regimes.
• Experimental assessment of aerosol effects on avalanche-based detection.

Main Results:

• Increased turbulence reduced breakdown sites in short-range mid-IR experiments, consistent with simulations.
• Long-wave-IR avalanche threshold focal volume remained robust, decreasing by only ~50% over 0.6 km in strong turbulence.
• Useful signals were extractable despite high aerosol concentrations (10^5 times typical levels).

Conclusions:

• Laser-induced avalanche breakdown shows resilience to atmospheric turbulence and aerosols for remote sensing.
• The technology holds promise for long-range detection of radioactive sources in real-world atmospheric conditions.
• Validated simulations aid in predicting performance and optimizing future detection systems.