Determination of the Relative Line Strengths of the A²A' ← X²A" and (200)←(000) transitions of HO₂

Author: Rosario-Ortiz, Fernando L.

Year: 2002

Degree: Master's thesis

Advisors: Okumura, Mitchio; Sander, Stanley P.

Committee Member: Unknown, Unknown

Option: Chemistry

DOI: 10.7907/vh44-fh68

Abstract

The hydroperoxyl radical (HO₂) has been one of the most studied triatomic radicals during the past few decades. Its roles in atmospheric chemistry through the HOₓ cycle as well as in processes such as combustion have made the study of this radical extremely important. In the past three decades the interest in the spectroscopy of this molecule has increased due in part by the need of detecting this radical in several different environments. Although its UV, mid- and far-IR transitions have been studied extensively, its near-IR transitions have not received much attention until recently. Among the transitions observed in this region, the A²A' ← X²A" first electronic transition and the (200)←(000) first OH overtone transition are two of the most important. These bands offer many advantages for detection of HO₂ in kinetic experiments and possibly in situ. Due to the importance of these two bands, information on their intensity is needed to measure accurately the concentration of HO₂. An apparatus has been constructed to measure the line strengths of the A ← X electronic transition at 1.43 µm and the (200)←(000) first OH overtone transition at 1.51 µm by diode laser absorption spectroscopy.

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