Simple method for gas temperature determination in CO₂-containing discharges

Area of Science:

• Plasma Physics
• Spectroscopy
• Gas Discharge Physics

Background:

• Accurate gas temperature measurement is crucial for understanding and controlling plasma processes.
• Traditional methods can be complex or limited in applicability to specific plasma environments.
• Carbon monoxide (CO) is a common molecule in various industrial and research plasmas.

Purpose of the Study:

• To develop a simple and effective method for determining gas temperature in CO-containing plasmas.
• To provide a formula for temperature control based on CO spectral synthesis.
• To validate the proposed method against established techniques.

Main Methods:

• Utilized the line ratio between two rotational peaks of the CO Angstrom rotational emission band.
• Developed a formula derived from CO spectral synthesis for temperature calculation.
• Validated the method in a CO2 flowing gas surfaguide microwave discharge (2.45 GHz).

Main Results:

• Successfully determined gas temperature using the CO Angstrom band line ratio method.
• The results showed good agreement when compared with the Boltzmann plot approach.
• Direct comparison of measured and calculated rotational spectra further validated the findings.

Conclusions:

• The reported method offers a simple and reliable way to measure gas temperature in CO plasmas.
• The spectral synthesis formula enables effective temperature control in relevant plasma systems.
• This technique provides a valuable alternative for gas temperature diagnostics in microwave discharges.