Accession Number:

ADA379013

Title:

State-to-State Thermal/Hyperthermal Collision Dynamics of Atmospheric Species

Descriptive Note:

Rept. 14 Dec 1996-14 Dec 1999

Corporate Author:

JOINT INST FOR LAB ASTROPHYSICS BOULDERCO

Personal Author(s):

• Nesbitt, David
• Harper, Warren
• Nizkorodov, Sergey
• Chapman, Bill
• Blackman, Brad

Report Date:

2000-03-01

Pagination or Media Count:

8.0

Abstract:

Shot-noise limited, direct absorption IR laser methods have been used to study i state-to-state reaction dynamics in crossed supersonic jets and ii temperature dependent studies of OH O3 chemical chain reaction kinetics via flash kinetic spectroscopy. In this first area. state-resolved studies of F H2 scattering have been completed from E 2.4 kcalsmole down to 0.30 kcalsmole, which by virtue of the high quantum state resolution in product detection have revealed contributions due to non-adiabatic reactions with spin orbit excited F4 atoms. These methods have been extended to F CH4, where high resolution IR laser Dopplerimetry can be used to extract product state velocities and thus differential cross section information at the state-to- state level. Time-resolved flash kinetic studies of the OHHO2O3 chemical chain reaction has been performed from 300K down to 180 K. providing first access to temperature conditions relevant to accurate modeling of the lower stratosphere. These methods have been extended to study airglow dynamics of highly rotationally excited OHv1N radicals formed from H O3 reactions.

Descriptors:

• *REACTION KINETICS
• *INFRARED LASERS
• *HYDROXYL RADICALS
• *ATMOSPHERIC CHEMISTRY
• HIGH RESOLUTION
• THERMAL ANALYSIS
• EMISSION SPECTROSCOPY
• DOPPLER SYSTEMS
• SUPERSONIC FLOW
• AIRGLOW
• STRATOSPHERE
• PARTICLE COLLISIONS

Subject Categories:

• Atmospheric Physics
• Lasers and Masers

Distribution Statement:

APPROVED FOR PUBLIC RELEASE