HR: 0800h
AN: SM41A-1173    [Abstracts]
TI: Oxygen and Proton Ion Implantation In The Solar Panel Coverglass Of GPS Satellites
AU: * Tuszewski, M
EM: mgtu@lanl.gov
AF: Los Alamos National Laboratory, ISR-1, Los Alamos, NM 87545 United States
AU: Harper, R
EM: rharper@lanl.gov
AF: Los Alamos National Laboratory, ISR-1, Los Alamos, NM 87545 United States
AU: Ciofalo, M
EM: Martin.R.Ciofalo@aero.org
AF: The Aerospace Corporation, 2350 E. El Segundo Bl., El Segundo, CA 90245 United States
AU: Meshishnek, M
EM: Michael.J.Meshishnek@aero.org
AF: The Aerospace Corporation, 2350 E. El Segundo Bl., El Segundo, CA 90245 United States
AU: Missirian, S
EM: Simone.M.Missirian@aero.org
AF: The Aerospace Corporation, 2350 E. El Segundo Bl., El Segundo, CA 90245 United States
AB: Global Positioning Satellites (GPS) have been experiencing an anomalous degradation of solar array power. This power loss, greater than the anticipated silicon cell damage by MeV electrons, remains unexplained. Low-energy ions have been identified as a possible cause of degradation of solar panel coverglass materials. Ion implantation in the (100-nm-thick) anti-reflection coating of the coverglass could cause darkening, and associated transmission loss. We investigate this hypothesis by irradiating various GPS flight configuration coverglass samples in simulated O+ and H+ environments based on modeling of the average ion environment at GPS orbit (20,000 km altitude). The ion implants (ion energies from 0.1 to 400 keV) are performed up to a 20-year-equivalent final dose. Coverglass samples from GPS Block IIA, IIR, IIF, and also from some geosynchronous satellites are implanted with several facilities: a plasma immersion ion implanter (up to 10 keV), a low-energy ion beam implanter (up to 60 keV), and a high-energy beam implanter (up to 400 keV). After each implant step, the optical transmission of the samples are measured from 200 to 900 nm. Implants to date suggest that a combination of oxygen and proton damage could account for part of the unexplained solar panel power loss. The latest results of this investigation will be presented.
DE: 2730 Magnetosphere: inner
DE: 2732 Magnetosphere interactions with satellites and rings
DE: 2794 Instruments and techniques
DE: 2799 General or miscellaneous
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005