Radiative Processes Following Laser Excitation of the A State of PO.
Abstract
Laser induced fluorescence in the (0,0) band of the A doublet sigma plus - X doublet pi system of the PO radical ( about 2470 Angstroms) has been used to study the radiative properties of the A state. Detection of fluorescence from the PO radical is of military interest because of the central role it plays in several proposed laser photlysis detection schemes necessary for quantitive detection of PO via laser induced fluorescence in the A-X system are presented. In this paper, results of measurements of several key parameters necessary for quantitative detection of PO via laser induced fluorecence scan of the emission are given. Fluorescence from the B doublet sigma plus state to the X state was observed (about 3250 Angstroms) when the A state was pumped by the laser. The branching ratio for emission from the A state to the lower B and X states was indirectly determined. The A state was found to have a very short free radiative lifetime, 9.68 + or - 0.47 ns. In the absence of quenching, the excited state decay is found to be primarily due to radiative processes. Upper limits were determined for the quenching rates of Ar and He carrier gases. Relative intensities of emission of the v'=0 progression in the A-X system were also measured. These intensities were used to determine the electronic transition moment function in the region of the equilibrium internuclear distance.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1986
- Accession Number
- ADA174934
Entities
People
- Anthony J. Kotlar
- Koon N. Wong
- William R. Anderson
Organizations
- Ballistic Research Laboratory