Laser-Plasma Spatiotemporal Cyanide Spectroscopy and Applications

Area of Science:

• Plasma Physics
• Laser-Induced Breakdown Spectroscopy (LIBS)
• Fluid Dynamics

Background:

• Laser-induced plasma (LIP) is crucial for material analysis and fusion energy research.
• Understanding hypersonic expansion dynamics is key to controlling plasma behavior.
• Diatomic molecular cyanide (CN) serves as a sensitive diagnostic probe in plasmas.

Purpose of the Study:

• To measure hypersonic expansion of laser-induced plasma.
• To investigate the properties of diatomic molecular cyanide (CN) plasma.
• To correlate spectral data with plasma characteristics like electron density and temperature.

Main Methods:

• Generating optical breakdown plasma using a 1064 nm Q-switched laser.
• Analyzing molecular spectra via line-of-sight (LOS) measurements.
• Utilizing high-speed shadowgraphy for plasma visualization.
• Applying integral inversion techniques for spatiotemporal analysis.

Main Results:

• Observed hypersonic expansion speeds exceeding Mach 5.
• Detected increased electron density near the shockwave via atomic carbon spectra.
• Measured higher excitation temperatures near the shockwave using CN spectra.
• Corroborated spectral findings with 5-nanosecond shutter speed shadowgraphs.

Conclusions:

• Laser-induced plasma exhibits significant hypersonic expansion.
• Plasma shockwaves are associated with elevated electron density and temperature.
• Spectral analysis of CN and atomic carbon provides valuable diagnostic information.
• Integral inversion techniques enable detailed spatiotemporal plasma distribution mapping.