Transient frequency-modulated spectroscopy: Application to the measurement of vector and scalar correlations in molecular photodissociation

Conference · Wed Apr 01 04:00:00 EST 1998

OSTI ID:585052

North, S W ^[1]; Hall, G E ^[2]

---

1. Texas A&M Univ., College Station, TX (United States). Dept. of Chemistry
2. Brookhaven National Lab., Upton, NY (United States)

An intrinsically time-resolved version of frequency-modulation (FM) spectroscopy has been recently developed and applied to the study of gas-phase photodissociation dynamics. Transient FM spectroscopy allows low background detection of radical species with shot-noise limited sensitivities, time resolution sufficient for detection of collisionless photoproducts, and frequency resolution characteristic of single-mode cw lasers. Methods for the quantitative analysis of Doppler-broadened FM line shapes to give velocity and rotational polarization information have been established permitting the measurement of scalar and vector properties of molecular fragmentation in exquisite detail. Several recent examples of the application of transient FM spectroscopy will be presented and discussed, including correlated scalar distributions in the dissociation of ketene from CH{sub 2}(a{sup 1} A{sub 1}) Doppler profiles, and the full vector correlation analysis of CN (X {sup 2}{Sigma}{sup +}) fragments arising from ICN dissociation.

• Research Organization: Brookhaven National Lab., Upton, NY (United States)
• Sponsoring Organization: USDOE Office of Energy Research, Washington, DC (United States)
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 585052
• Report Number(s): BNL--65184; CONF-980135--; ON: DE98002800
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
DISSOCIATION
FREQUENCY MODULATION
KETENES
LASERS
NOISE
PHOTOCHEMICAL REACTIONS
SPECTROSCOPY
TIME RESOLUTION
VELOCITY