The BeppoSAX 1-8 keV cosmic background spectrum

The spectrum of the 1.0-8.0 keV cosmic X-ray back ground (CXB) at galactic latitudes >\25\degrees has been measured using the BeppoSAX LEGS and MECS i nstruments. The spectrum is consistent with a power-law of photon index 1.4 0 +/- 0.04 and normalization 11.7 +/- 0.5 photon cm(-2) s(-1) keV(-1) sr(-1 ) at 1 keV. Our results are in good agreement with previous ROSAT PSPC (Geo rgantopuolos et al. 1996), ASCA GIS (Miyaji et al. 1998) and rocket (McCamm on & Sanders 1990) measurements. On the contrary, previous measurements wit h the HEAO1 A2 (Marshall et al. 1980) and the ASCA SIS (Gendreau et al. 199 5) instruments, are characterized by normalizations which are respectively 35% and 25% smaller than ours.