Cover Page/Proposal Summary

ROSS-00    NRA 00-OSS-01

Date Due: 4/28/2000

NASA PROCEDURE FOR HANDLING PROPOSALS 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: Tenuous Atmospheres

Major Equipment Proposal? No

Do you intend to submit an Education/Public Outreach (E/PO) proposal? No

Proposal Title:

Effects of Radiation on Desorption of Alkalis from Mineral and Ice Surfaces: Relation to Origins of Alkali Vapor in Planetary Atmospheres

Abbreviated Proposal Title:

Desorption of Alkali Atoms from Minerals and Ices

Principal Investigator:

Dr. Theodore Madey Physics and Astronomy Rutgers University 136 Frelinghuysen Rd. Piscataway, NJ 08854-8019 Phone: 732-445-5185   Fax: 732-445-4991   E-mail: madey@physics.rutgers.edu

Signature	Date
_____________________________________	____________

Co-Investigators and Collaborators:
Type	Name	Affiliation	E-mail
Sci Collab	Prof. Vladimir Ageev	A. F. Ioffe Physico-Technical Institute, Russia	ageev@ms.ioffe.rssi.ru
Sci Collab	Prof. Robert E. Johnson	Univ. of Virginia	rej@virginia.edu
Sci Co-I	Dr. Boris V. Yakshinskiy	Rutgers University	yaksh@physics.edu

Proposal Summary:

We propose to use laboratory methods to address the origins of alkali vapors (Na, K) in the atmospheres of the planet Mercury, the Moon, and Europa. We will use a variety of ultrahigh-vacuum surface science techniques to make measurements of thermal desorption and radiation-induced desorption (i.e., by electrons, photons, and ions) of Na and K from the surfaces of model minerals characteristic of planetary and lunar surfaces, and from ice surfaces characteristic of Europa. We will build on our recent studies of desorption of Na from SiO_{2} surfaces, where we have shown that photon-stimulated desorption is a probable major source process for Na in the lunar atmosphere. Substrates will include amorphous and crystalline H_{2}O ice surfaces, amorphous and crystalline Al_{2}O_{3}, and amorphous SiO_{2}. We will also study more complex mineral substrates (olivine or plagioclase) as closer surrogates for the lunar and Mercurian surfaces; we will apply to NASA for lunar samples. Adsorption (sticking) probabilities, desorption yields, energy thresholds and kinetic energy distributions will be determined for both Na and K, and the effect of substrate electronic properties (e.g., bandgap) will be determined. We will test a one-electron charge-transfer model of photon stimulated desorption, which may provide insights into why Na and K (but not Mg and Ca) are seen in the atmospheres. We expect that these data will provide useful input to modelers and theorists who are simulating tenuous planetary atmospheres.

Certification of Compliance with Applicable Executive Orders and U.S. Code By submitting the proposal identified in this Cover Sheet/Proposal Summary in response to this NRA or AO, the Authorizing Official of the proposing institution (or the individual proposer if there is no proposing institution) as identified below: certifies that the statements made in this proposal are true and complete to the best of his/her knowledge; agrees to accept the obligations to comply with NASA award terms and conditions if an award is made as a result of this proposal; and confirms compliance with all provisions, rules, and stipulations set forth in the three Certifications contained in this NRA [namely, (i) Certification Regarding Debarment, Suspension, and Other Responsibility Matters Primary Cover Transactions, (ii) Certification Regarding Lobbying, and (iii) Certification of Compliance with the NASA Regulations Pursuant to Nondiscrimination in Federally Assisted Programs]. Willful provision of false information in this proposal and/or its supporting documents, or in reports required under an ensuing award, is a criminal offense (U.S. Code, Title 18, Section 1001).