Cosmic X-ray background and Earth albedo Spectra with Swift/BAT
  We use Swift/BAT Earth occultation data at different geomagnetic latitudes to derive a sensitive measurement of the Cosmic X-ray background (CXB) and of the Earth albedo emission in the 15--200 keV band. We compare our CXB spectrum with recent (INTEGRAL, BeppoSAX) and past results (HEAO-1) and find good agreement. Using an independent measurement of the CXB spectrum we are able to confirm our results. This study shows that the BAT CXB spectrum has a normalization ~8(+/-3)% larger than the HEAO-1 measurement. The BAT accurate Earth albedo spectrum can be used to predict the level of photon background for satellites in low Earth and mid inclination orbits. 
M. Ajello, J. Greiner, G. Sato, D. R. Willis, G. Kanbach, A. W.   Strong, R. Diehl, G. Hasinger, N. Gehrels, C. B. Markwardt...