Accession Number:

ADA341374

Title:

Energetic and Steric Effects in Ion/Surface Reactive Scattering

Descriptive Note:

Final rept. 15 Jan 95-14 Jan 98

Corporate Author:

NOTRE DAME UNIV IN DEPT OF CHEMISTRY AND BIOCHEMISTRY

Personal Author(s):

Report Date:

1998-03-14

Pagination or Media Count:

12.0

Abstract:

The principal investigator explored chemical reactions between small molecular ions and solid surfaces in order to simulate reactions on spacecraft surfaces in a low-earth-orbit environment. The surfaces were prepared in ultrahigh vacuum, and the ions were accelerated to translational energies between 5 and 100 eV before they collided with the surface target. The scattered reaction products were detected with energy-, mass-, and angular resolution. Results are reported for dissociative scattering of OCS on Ag111, where three different mechanisms were assigned for the three observed fragmentation pathways. Experiments were also conducted on NO reacting with OAg111 and OAl111. Here, an atom abstraction channel led to the scattering of NO2. Finally, prolonged bombardment of a silicon nitride surface by low energy O ions was observed to induce irreversible damage in the nitride thin film.

Subject Categories:

  • Physical Chemistry
  • Astronautics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE