Laser allows long-range detection of radioactive materials, Pg 22

Key Highlights

Breakthrough in Radiation Detection

• U.S. physicists demonstrate a laser-based method using carbon-dioxide lasers to detect radioactive materials from a distance.
• Technique uses avalanche breakdown, where charged particles ionize air and generate plasma.

Working Mechanism

• Laser emits infrared radiation (9.2 micrometres) to accelerate electrons.
• Electrons collide, releasing more electrons, producing optical backscatter.
• Detects alpha particles from a source located 10 m away10x better than earlier methods.

Potential for Long-Range Detection

• Paves way for detecting gamma-ray sources (e.g., Cs-137) from up to 100 m away.
• Critical for nuclear safety, national defense, and emergency response.

Advantages of the Technique

• Highly sensitive, can detect low concentrations.
• Long-wavelength lasers reduce noise and enhance backscatter detection.
• Can detect through airborne seed electron plasma for improved range.

Limitations

• Scaling to >1 km range faces issues like signal loss, atmospheric interference.
• Requires larger optics and lasers.

Analysis & Way Forward

• A promising tool for homeland security and nuclear non-proliferation efforts.
• India could explore integrating such technologies into DRDO and nuclear monitoring frameworks.

Mains Mock Question:

"Discuss the significance of laser-based long-range detection of radioactive materials for national security. What are the potential applications and limitations of this technology?"