Laser air plasma expansion by microwaves

Area of Science:

• Plasma Physics
• Spectroscopy

Background:

• Microlasers generate air plasma.
• Microwave application is explored for plasma enhancement.

Purpose of the Study:

• Investigate microwave impact on microlaser-generated air plasma expansion.
• Assess changes in plasma temperature and electron density.
• Evaluate potential for improved laser-induced breakdown spectroscopy (LIBS).

Main Methods:

• Generated air plasma using a microlaser (1 mJ).
• Applied microwaves to enhance plasma growth.
• Visualized plasma expansion with a phone camera.
• Recorded plasma emissions with a high-resolution spectrometer.
• Analyzed emissions for temperature and electron density using software.

Main Results:

• Observed a 400-fold increase in plasma volume with microwave enhancement.
• Recorded increased plasma temperature and decreased electron density under microwave exposure.
• Indicated the formation of nonequilibrium plasmas.
• Noted a minor shift in electron temperature, suggesting sustained plasma characteristics.

Conclusions:

• Microwave application significantly enhances air plasma volume.
• Microwave-induced changes in plasma parameters suggest nonequilibrium conditions.
• Findings indicate potential for microwave-assisted LIBS analytical performance improvement.