Peak-power dependence of rovibronic populations below the quasicontinuum during IR multiphoton absorption
Experimental studies on IR multiphoton absorption and dissociation have generally provided insight only into the relationship of IR laser characteristics such as power, wavelength, and mode structure to the observables dissociation yields, average number of photons absorbed, and product energy distribution. As a result, theoretical modeling of absorption at levels below the quasicontinuum has been based on facts somewhat removed from the actual phenomenon of interest. The experiments presented here provide information on the unperturbed rotational/vibrational populations of levels subsequent to IR excitation at levels below 4000 cm/sup -1/ of energy. The experiment makes use of molecular beam techniques in conjunction with IR-visible double resonance. A CO/sub 2/ laser of known pulse duration prepares vibrationally excited thiophosgene, Cl/sub 2/C = S. The absorbing transition is 2 ..nu../sub 4/. A tunable nitrogen-pumped dye laser scans the visible excitation spectrum to probe the perturbed rotational-vibrational populations of the pumped mode. Because the electronic transition is electric dipole forbidden, combination hot bands having the appropriate quantum numbers of the ground state are used in the analysis.
- Research Organization:
- Brookhaven National Lab., Upton, NY (USA)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC02-76CH00016
- OSTI ID:
- 6524299
- Report Number(s):
- BNL-28758; CONF-810609-1
- Resource Relation:
- Conference: 8. international symposium on molecular beams, Cannes, France, 1 Jun 1981
- Country of Publication:
- United States
- Language:
- English
Similar Records
Multiphoton dissociation of ethyl chloride at 3. 3. mu. m: Excitation mechanism and rate equations analysis
Multiphoton dissociation and thermal unimolecular reactions induced by infrared lasers. [REAMPA code]
Related Subjects
ABSORPTION SPECTROSCOPY
LASER RADIATION
PHOSGENE
ROTATIONAL STATES
VIBRATIONAL STATES
DISSOCIATION
INFRARED RADIATION
MATHEMATICAL MODELS
MOLECULES
CARBONIC ACID DERIVATIVES
ELECTROMAGNETIC RADIATION
ENERGY LEVELS
EXCITED STATES
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
RADIATIONS
SPECTROSCOPY
640304* - Atomic
Molecular & Chemical Physics- Collision Phenomena