Radiation environment of the microelectronics and photonics test bed as measured by CREDO-3

The Cosmic Radiation Environment Dosimetry experiment is providing data on particle fluxes and linear energy transfer spectra for inner belt protons, cosmic rays and solar particles in order to correlate with device behaviour in the MPTB experiments and to provide tests of environment models. Particle fluxes are related to geomagnetic co-ordinates in order to explain the observed time variations around the orbit and the differences between odd and even orbits. Cosmic-ray fluxes are slowly decreasing as solar maximum is approached. Outer-belt electrons show large variations and were particularly enhanced during late August to November 1998. Several solar particle events have been observed. Integral linear energy transfer (LET) spectra for these show both lower intensities and a lack of enhancement at high values of LET when compared with the October 1989 event which is commonly used as a worst case.