PROPOSAL NUMBER 99-1 25.01-4770 (Chron: 992541 )
PROJECT TITLE
Chemical Flow Modeling for Enhanced Analysis of Contamination Experiments
TECHNICAL ABSTRACT (LIMIT 200 WORDS)
Underlying the many models for simulating space contamination effects are the rates for fundamental chemical processes. The rates are generally not known and are difficult to measure, but are critical for meaningful simulations. Molecular Beam Experiments (MBE), which are typically used to determine them, produce large uncertainties in derived rates arising from uncertainties in the flow field of reacting molecules, and only cover a small portion of the parameter space of interest. We propose an analysis approach coupling fundamental computational chemistry tools to the SOCRATES Direct Simulation Monte Carlo (DSMC) flow field code to provide an accurate simulation of MBEs. This will enable a much more accurate extraction of fundamental rates from MBE data and also allow the rate constant to be extrapolated with confidence to the entire application parameter space of interest. The Phase I technical objectives are: (1) Adapt SOCRATES to simulate MBEs, (2) Validate the approach using gas phase MBE data, and (3) Formulate a gas-surface computational chemistry-flow field model. The extension of the approach to model gas-surface MBE data is more complex and will be formulated in Phase I for implementation and experimental validation in Phase II.
POTENTIAL COMMERCIAL APPLICATIONS
The DSMC gas/surface chemistry software product provides a new and unique capability for simulating and analyzing chemical processes on and near surfaces. Commercial applications include the semiconductor industry chemical vapor deposition and surface modification processes simulation, surface catalysis modeling, surface coating and corrosion modeling, and non-equilibrium combustion modeling. NASA applications include spacecraft surface contamination (from outgassed, vented, and plume species), spacecraft sensor optical contamination, and degradation of spacecraft surfaces from exposure to the space environment.
NAME AND ADDRESS OF PRINCIPAL INVESTIGATOR (Name, Organization Name, Mail Address,
City/State/Zip)
Dr. Matthew Braunstein
Spectral Sciences, Inc.
99 South Bedford Street, #7
Burlington , MA 01803 - 5169
NAME AND ADDRESS OF OFFEROR (Firm Name, Mail Address, City/State/Zip)
Spectral Sciences, Inc.
99 South Bedford Street, #7
Burlington , MA 01803 - 5169