PDS: The Planetary Atmospheres Node
Cover Page/Proposal Summary
ROSS-99 NRA 99-OSS-01
Date Due: 5/3/99
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This proposal shall be used and disclosed for evaluation purposes only, and a copy of this Government notice shall be applied to any reproduction or abstract thereof. Any authorized restrictive notices that the submitter places on this proposal shall also be strictly complied with. Disclosure of this proposal for any reason outside the Government evaluation purposes shall be made only to the extent authorized by the Government. |
| Proposal Type: New Proposal |
| Proposal Category: Atmosphere Structures and Particles |
| Major Equipment Proposal? No |
| Do you intend to submit an Education/Public Outreach (E/PO) proposal? No |
| Proposal Title: |
| Electron-Impact Dissociation and Excitation of Molecules and Molecular Ions |
| Abbreviated Proposal Title: |
| Electron-Impact Dissociation |
| Principal Investigator: |
| Dr.
Kurt Becker Dept. of Physics & Engn. Phys. Stevens Institute of Tech. River Street & Sixth Street Hoboken, NJ 07030 Phone: (201) 216-5671 Fax: (201) 216-5638 E-mail: kbecker@stevens-tech.edu |
| Signature | Date |
| _____________________________________ | ____________ |
| Co-Investigators and Collaborators: | |||
| NONE | |||
Proposal Summary:
We propose to continue our laboratory studies of electron collisions with molecules, ions, and radicals relevant to processes in planetary and cometary atmospheres. This renewal proposal addresses two new research areas, (i) the electron-impact induced dissociation of selected molecules (H2O, CH3OH, CH4, SO2, HCN, CH3CN, NH3) into neutral ground-state fragments using a combination of electron scattering and laser-induced fluorescence techniques and (ii) optical emissions from electron-impact excited singly-charged molecular ions such as N2+, O2+, NH+, CO+, OH+, NO2+, and CO2+ using a new crossed-beams apparatus incorporating a novel high-current electron gun and a well-characterized mass-selected ion beam produced by a magnetic sector-field mass spectrometer. Both types of electron collisions are of crucial importance in the modeling of the energy balance and the key reaction pathways and processes in various planetary and cometary atmospheres, yet neither process has received much attention due to many inherent complications in studying these processes. Areas of Impact of the proposed research: ground-based and earth-orbit observations provided a wealth of data on cometary environments which elude to the origin and the evolution of comets. Modeling activities focus on the identification of molecules which produce the ionic and neutral fragments. The various instruments aboard Giotto recorded the presence of significant amounts of ions such as OH+, CH+, CO+, neutral fragments such as CN and NH, and heavier molecules such as HCN, CH3CN, and NH3. The three missions to Jupiter and its satellites still leave many unanswered questions regarding the key processes in e.g. the Io torus. Electron impact dissociation of molecules is believed to be an important process in the Io torus. CH, HCN, CN, CO, NH3, NH2, NH, H2O, and OH and some molecular and radical ions were found in the atmospheres of Jupiter and Saturn and near the outer planets Uranus and Neptune.
