LIF measurements of radiative lifetimes of the C2(B'1Σ+g) state

✍ Scribed by Mengxiong Gong; Yihan Bao; Randall S. Urdahl; William M. Jackson

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 540 KB
• Volume: 217
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(93)e1374-p

✦ Synopsis

The 193 nm photolysis of acetylene has been used as a source of &(B 'Z: ) radicals, which are subsequently detected by laserinduced fluorescence technique. The pressure-dependent collisional lifetimes of this radical are experimentally determined by delaying the probe laser with respect to the photolysis laser, thus allowing extraction of the pseudo-first-order rate constants. Stem-Volmer plots of these rate constants versus pressure yield the natural radiative lifetimes of the state. Three different rotational levels of the C2 (B' '8: ) state were studied. The natural radiative lifetimes were 11.6 f 1.4 us and 10.4 k 1.9 us for the D'= 0, J'= 8 and J'= 14 levels, respectively, and 8.3 f 1.9 us for the II'= 1, J'= 8 level. These values are in reasonable agreement with the recent theoretical calculations. In addition, the second-order rate constants for the excited state quenching by Ar have also been calculated from the data.