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Prediction of LDEF exposure to the ionizing radiation environmentPredictions of the LDEF mission's trapped proton and electron and galactic cosmic ray proton exposures have been made using the currently accepted models with improved resolution near mission end and better modeling of solar cycle effects. An extension of previous calculations, to provide a more definitive description of the LDEF exposure to ionizing radiation, is represented by trapped proton and electron flux as a function of mission time, presented considering altitude and solar activity variation during the mission and the change in galactic cosmic ray proton flux over the mission. Modifications of the AP8MAX and AP8MIN fluence led to a reduction of fluence by 20%. A modified interpolation model developed by Daly and Evans resulted in 30% higher dose and activation levels, which better agreed with measured values than results predicted using the Vette model.
Document ID
20040121327
Document Type
Reprint (Version printed in journal)
Authors
Watts, J. W.
(NASA Marshall Space Flight Center Huntsville AL United States)
Armstrong, T. W.
Colborn, B. L.
Date Acquired
August 22, 2013
Publication Date
November 1, 1996
Publication Information
Publication: Radiation measurements
Volume: 26
Issue: 6
ISSN: 1350-4487
Subject Category
Life Sciences (General)
Distribution Limits
Public
Copyright
Other
Keywords
Flight Experiment
unmanned
LDEF Project
long duration
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