dc.creator Lee, Shih-Huang en_US dc.creator Chen, I-Chia en_US dc.date.accessioned 2007-11-20T17:14:25Z dc.date.available 2007-11-20T17:14:25Z dc.date.issued 1995 en_US dc.identifier 1995-TJ-05 en_US dc.identifier.uri http://hdl.handle.net/1811/29853 dc.description Author Institution: National Tsing Hua University, Hsinchu, Taiwan 30043, Republic of China en_US dc.description.abstract Formyl radicals produced from photolysis of acetaldehyde at 310 nm were supersonically cooled and detected via the $\tilde{B}-\tilde{X}$ transition using the laser-induced fluorescence (LIF) technique. Spectra at resolution $0.16 cm^{-1}$ and fluorescence lifetimes of HCO $\tilde{B} (0,0,0), (0,0,1)$ levels were measured. The observed lifetimes decrease rapidly with variation of the rotational quantum number $K_{a}$ from 0 to 2 but slowly with the rotational quantum number N from 0 to 8. Experimental data indicate that the $\tilde{B}$ state is coupled to a predissociating state via an $\alpha$-type Coriolis interaction, to account for the rotationally dependent lifetime for the low vibrational levels of the HCO $\tilde{B}$ state. Correction of the fluorescence quantum yield for individual rotational states is necessary to obtain accurate ground state populations by LIF when using the $\tilde{B}-\tilde{X}$ transitions. The intensity distribution of the two spin states observed implies a negative value of the spin-rotation parameter for the $\tilde{B}$ state, in contrast with the ground electronic state. en_US dc.format.extent 62607 bytes dc.format.mimetype image/jpeg dc.language.iso English en_US dc.publisher Ohio State University en_US dc.title PREDISSOCIATION MECHANISM AND SPIN-ROTATION CONSTANT OF THE HCO $\tilde{B}^{2} A'$ STATE en_US dc.type article en_US
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