Diatomic Carbon Measurements with Laser-Induced Breakdown Spectroscopy

In this thesis, investigation of well-known carbon Swan spectra is of primary interest. Combustion processes and/or explosion of hydrocarbon fuels cause occurrence of the Swan band system that originates from diatomic carbon. Physical characteristics of low-temperature stars and the interstellar medium can also reveal the Swan bands. The diatomic carbon molecule shows that its lowest rotational levels are sensitive to temperature variation, and higher rotational levels are sensitive to the surrounding gas density and the radiation field. In addition, carbon is a crucial element for life and is the 4th most abundant element; therefore, it is important to ascertain accurately the origin and processes in which it forms. Laser induced breakdown spectroscopy experiments are conducted to record highly-excited Swan spectra in emission. Laser ablation of graphene is investigated with 190 milliJoule, 13 nanosecond Nd:YAG pulses at a wavelength of 1.064 micrometer. Accurate line-strengths are utilized in computation and modeling of the recorded Swan spectra. The results indicate temperatures in the range of 4500 to 6500 K for time delays from optical breakdown in the range of 100 to 10 microseconds.