effects community as more resources are brought to bear on the problem. II-67 ACKNOWLEDGMENTS The author is grateful for the continuing support, encouragement, and camaraderie of the Radiation Technology and Assurance Department at Sandia National Laboratories. Were it not for the accumulated expertise in the department and hours of stimulating discussions with Peter Winokur, Fred Sexton, Marty Shaneyfelt, Jim Schwank, Dan Fleetwood, and a host of others, the understanding of basic mechanisms of single-event effects represented in this paper would not have been possible. I especially want to thank my family and friends for their patience and understanding as I undertook this work, and especially my wife Melanie whose encouragement was unwavering. I would also like to acknowledge the partial support of Lew Cohn and the Defense Threat Reduction Agency. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under contract DE-AC04-94AL85000. II-68 REFERENCES J.L. Barth, "Modeling Space Radiation Environments," 1997 IEEE NSREC Short Course, Snowmass, CO. C.S. Dyer, "Space Radiation Environment Dosimetry," 1998 IEEE NSREC Short Course, Newport Beach, J. Feyman and S. B. Gabriel, "High-energy charged particles in space at one astronomical unit," IEEE Trans. Nucl. Sci., vol. 43, no. 2, pp. 344-352, 1996. M. S. Gussenhoven, E. G. Mullen, and D. H. Brautigam, "Improved understanding of the Earth's radiation belts from the CRRES satellite," IEEE Trans. Nucl. Sci., vol. 43, no. 2, pp. 353-368, 1996. E. G. Stassinopoulos, G. J. Brucker, D. W. Nakamura, C. A. Stauffer, G. B. Gee, and J. L. Barth, "Solar flare proton evaluation at geostationary orbits for engineering applications," IEEE Trans. Nucl. Sci., vol. 43, no. 2, pp. 369-382, 1996. C. S. Dyer, A. Sims, and C. Underwood, "Measurements of the SEE environment from sea level to GEO using the CREAM and CREDO experiments," IEEE Trans. Nucl. Sci., vol. 43, no. 2, pp. 383-402, 1996. E. J. Daly, J