Paper PS-MoA3
Using Broadband Absorption Spectroscopy to Elucidate Energy Partitioning and its Impact on Surface Reactivity

Monday, October 19, 2015, 3:00 pm, Room 210A

The partitioning of energy within plasma systems is of vital importance to plasma chemistry as it provides insight into reactivity via possible species formation and decomposition mechanisms as well as its significant contribution to surface reactivity of individual plasma species. Here, such investigations are used to determine the internal and kinetic energies of species within a variety of inductively coupled plasma systems. To obtain this information, broadband absorption spectroscopy (BAS) and the imaging of radicals interacting with surfaces (IRIS) technique were utilized to determine species energetics (vibrational, rotational, and translational temperatures). In particular, the vibrational and rotational temperatures of NO, N₂, OH, and O₂ in various gas mixtures are measured, indicating significantly higher vibrational temperatures (i.e. >3000K) than rotational temperatures (i.e. <1000K) are obtained. One focus of this work is the development of a BAS system and the impact of various methods of data collection on determined temperatures evaluated using different computational models. These data are also used to demonstrate the relationship between internal energetic and observed surface scatter coefficients (S) for NO, OH, and other plasma species, which is directly related to surface reactivity (R). Such observations allow for unique insight into these plasma systems and the integral role energy partitioning plays in the assessment and understanding of complex plasma chemistry.