CN and C₂ Spectroscopy on the Pulsed Ablation of Graphite in the Visible Spectrum

Author

Brandon A. Pierce

Date of Award

3-2020

Document Type

Thesis

Degree Name

Master of Science

Department

Department of Engineering Physics

First Advisor

Kevin Gross, PhD

Abstract

An experimental study was conducted on the nanosecond pulsed laser ablation of graphite using a KrF laser at a fluence of 3.8 J/cm² in Air, Ar, He, and N₂. Optical emissions spectroscopy revealed the C₂ Swan sequences and the CN Violet sequences. A spectroscopic model was developed to extract the molecular rotational and vibrational temperatures of each excited species for t=0.5-10 microseconds after laser irradiation. The rovibrational temperatures were found to vary with background gas for the CN Violet; however, only the vibrational temperature varied between He and the other background gases for C₂ Swan. The rotational and vibrational temperatures were not in equilibrium for both the C₂ Swan and CN Violet.

AFIT Designator

AFIT-ENP-MS-20-M-111

DTIC Accession Number

AD1109191

Recommended Citation

Pierce, Brandon A., "CN and C₂ Spectroscopy on the Pulsed Ablation of Graphite in the Visible Spectrum" (2020). Theses and Dissertations. 3892.
https://scholar.afit.edu/etd/3892