Accession Number : ADA476803


Title :   Space Particle Hazard Measurement and Modeling


Descriptive Note : Final rept. 1 Oct 2001-30 Sep 2007


Corporate Author : AIR FORCE RESEARCH LAB HANSCOM AFB MA


Personal Author(s) : Metcalf, James ; Albert, Jay ; Brautigam, Donald ; Ginet, Gregory ; Golightly, Michael ; Knorring, Christine ; Lai, Shu ; Murad, Edmund ; Young, Shawn


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a476803.pdf


Report Date : 30 Nov 2007


Pagination or Media Count : 46


Abstract : This report describes R&D to measure and model the near-earth space environment and the effects of the environment on spacecraft in orbit. Data from two Compact Environmental Anomaly Sensors (CEASE) were analyzed to derive flux spectra of energetic particles. Data from CEASE were also used to create maps of proton fluxes in the South Atlantic Anomaly at multiple altitudes between 400 and 1650 km. A new approach to modeling the diffusion of energetic electrons in the radiation belts was developed. This approach uses a coordinate transformation that eliminates the mathematically difficult coefficients of cross-diffusion in pitch angle and momentum that appear in the conventional diffusion equation. MHD modeling was used to study trapping and detrapping of solar energetic protons in the magnetosphere. Environmental effects on spacecraft were investigated, primarily using data from satellites operated by Los Alamos National Laboratory. Effects included surface charging, deep dielectric charging, and micrometeoroid impacts. The research determined the critical temperature for spacecraft charging, which is a characteristic of each surface material. Other effects studied were the role of spacecraft spin in charging, the effects of emitted electron beams on spacecraft, and charge mitigation methods.


Descriptors :   *HAZARDS , *SPACE ENVIRONMENTS , *CHARGED PARTICLES , MEASUREMENT , INTERACTIONS , MAGNETOSPHERE , RADIATION BELTS , MAGNETOHYDRODYNAMICS , ELECTRON BEAMS , TRAPPING(CHARGED PARTICLES) , MODELS , SPACECRAFT


Subject Categories : Astrophysics
      Nuclear Physics & Elementary Particle Physics
      Unmanned Spacecraft


Distribution Statement : APPROVED FOR PUBLIC RELEASE