Space Radiation Shielding Calculation by Approximate Model for LEO Satellites

  • Published : 2004.02.01

Abstract

Two approximate methods for a cosmic radiation shielding calculation in low earth orbits were developed and assessed. Those are a sectoring method and a chord-length distribution method. In order to simulate a change in cosmic radiation environments along the satellite mission trajectory, IGRF model and AP(E)-8 model were used. When the approximate methods were applied, the geometrical model of satellite structure was approximated as one-dimensional slabs, and a pre-calculated dose-depth conversion function was introduced to simplify the dose calculation process. Verification was performed with mission data of KITSAT-1 and the calculated results were also compared with detailed 3-dimensional calculation results using Monte Carlo calculation. Dose results from the approximate methods were conservatively higher than Monte Carlo results, but were lower than experimental data in total dose rate. Differences between calculation and experimental data seem to come from the AP-8 model, for which it is reported that fluxes of proton are underestimated. We confirmed that the developed approximate method can be applied to commercial satellite shielding calculations. It is also found that commercial products of semi-conductors can be damaged due to total ionizing dose under LEO radiation environment. An intensive shielding analysis should be taken into account when commercial devices are used.

Keywords

References

  1. R.E. Prael, & H. Lichtenstein, User Guide to LCS: The Lahet Code System, p.5-20, Los Alamos National Laboratory, New Mexico(1989)
  2. L.S. Waters, MCNPX Users Manual, Version 2.1.5, p.15-54., Los Alamos National Laboratory, New Mexico(1999)
  3. J. Barth, Modeling Space Environment, in IEEE NSREC Short Courses, pp.22-48, IEEE Publishing Services, New Jersey(1997)
  4. J.W. Haffner, Radiation and Shielding in Space, p. 107-175, Academic Press, New York(1967)
  5. C.E. Barton, 'International Geomagnetic Reference Field: Seventh Generation,' J. Geomagnetic & Geoelectric, Vol. 49, p.123-148, (1997) https://doi.org/10.5636/jgg.49.123
  6. D.W. Sawyer and J.I. Vette, Ap-8 Trapped Proton Environment for Solar Maximum and Minimum, NSSDC/WDC-A-R&S 76-06, (1976)
  7. J.I. Vette, The NASA/National Space Data Center Trapped Radiation Environment Model Program(1964-1991), NSSDC/WDC-R&S 91-29, (1991)
  8. J.D. Kinnison, Achieving Reliable, Affordable Systems, in IEEE NSREC Short Courses, p.14-16, IEEE Publishing Services, New Jersey(1998)
  9. S.J. Kim, Y.H. Shin, & K.W. Min, 'Simulation of Shielding Effects on The Total Dose Observed in TDE of KITSAT-1,' Journal of Astronomy and Space Sciences, 18, 71-80 (2001)
  10. M.W. Shin & M.H. Kim, 'Comparison of Approximate Models for High Energy Cosmic Radiation Shielding Calculation,' Journal of Astronomy and Space Sciences, 19, p.151-162 (2002) https://doi.org/10.5140/JASS.2002.19.2.151
  11. W.R. Yucker & J. R. Lilley, CHARGE Code for Space Radiation Shielding Analysis, p.6-24, McDonnell Douglas Astronautics Co., California(1969)
  12. Gussenhoven, M. S., Mullen, E. G., Bell, J. T., Madden, D. & Holeman, E, APEXRAD: low altitude orbit dose as a function of inclination, magnetic activity and solar cycle, IEEE Transactions on Nuclear Science, Vol. 44, 1997 https://doi.org/10.1109/23.659031
  13. Petersen, E. L. Predictions and observations of SEU rates in space, IEEE Transactions on Nuclear Science, Vol. 44, 1997 https://doi.org/10.1109/23.659033
  14. Space Radiation Effects Handbook, p.3-7, Space Radiation Inc.(1997)