ClF/sub x/--H/sub 2/ chemical lasers (x=1,3,5): vibration--rotation emission by HF from states with high rotational excitation

Journal Article · Sat Oct 01 04:00:00 EDT 1977 · J. Chem. Phys.; (United States)

OSTI ID:7298487

Krogh, O D; Pimentel, G C

Stimulated vibration--rotation emission by HF has been observed from states with high rotational excitation following flash photolysis of ClF/sub x/--H/sub 2/--Ar mixtures (ClF, ClF/sub 3/, ClF/sub 5/). We report here only those observations connected with the very high rotational states J'> or =9 (e.g., up to v=1, J=20 and v=2, J=15) which are found to emit under grating-selective conditions. The patterns of emission indicate that direct population of the high J states by the vibrational pumping reaction(s) can be ruled out. Neither is the behavior consistent with Boltzman equilibration. The late threshold times and extended durations point to an energy transfer mechanism that involves rapid V..-->..R deactivation with large ..delta..J coupled with V..-->..V up pumping in HF/sup double-daggerdouble-dagger/ collisions to give a cumulative increase in rotational energy. Thus, V..-->..V and V..-->..R processes divert vibrational excitation into rotational excitation where it will tend to ''pool'' in high J states for which rotational equilibration is a slow process. These high J, P branch laser emissions reflect the role of rotational degrees of freedom in reaction dynamics and they furnish distinctive clues to energy processes that can influence significantly the efficiency and spectral composition of chemical laser emission.

• Research Organization: Department of Chemistry, University of California, Berkeley, California 94720
• OSTI ID: 7298487
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 67:7; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420300* -- Engineering-- Lasers-- (-1989)
CHEMICAL LASERS
EMISSION
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EXCITATION
EXCITED STATES
HYDROFLUORIC ACID
HYDROGEN COMPOUNDS
INORGANIC ACIDS
LASERS
ROTATIONAL STATES
STIMULATED EMISSION