Rotationally-resolved Spectral Analysis Of Oxygen Molecular Cation And Observation Of Its Anion

Oxygen ion is one of the most important ions in the lower ionosphere,gas discharge containing oxygen,combustion process and many kinds of celestial bodies. Its spectral study,especially the finger-print-like rotationally-resolved one,is of great essences in the relevant fields.This thesis focuses on the rotationally-resolved spectral study on the highly vibrational excited hot bands both in the doublet and quartet system of O₂⁺.The spectrum is observed employing optical heterodyne velocity modulation spectroscopy (OH-VMS) in the range of 11900～12800 cm^-1.One hundred and thirty-six lines of the(4,20) band in the second negative system(A²âˆ_u-X²âˆ_g) of O₂⁺ are assigned.A nonlinear least-squares fitting is used to obtain precise molecular constants combining with those of the(4,19) and(6,20). Our results show more or less improvement of the constants in precision.Additionally,about 200 spectral lines of the(2,7) band in the first negative system(b⁴∑₈^- -a⁴∏_u) of O₂⁺ are analyzed,which results in precise molecular constants involved.Furthermore,the RKR potential curves of both the a and b quartet states,the band origins,and the Franck-Condon factors of O₂⁺ are derived based on the latest equilibrium constants.Finally,the rovibronic spectrum of the O₂^- are observed and a tentative analysis is stated.