The scientific and technical drivers of ECLAIRs: the x- and gamma-ray telescope onboard the GRB mission SVOM

ECLAIRs is an X and gamma-rays wide-field coded mask camera onboard the Chinese-French mission SVOM (Space-based multi-wavelength Variable Objects Monitor) that is dedicated to study Gamma-ray bursts (GRBs). SVOM is due to be launched in 2015 in a low Earth orbit (630 km circular orbit with 30° inclination) for a three years duration. SVOM is designed to operate "a la SWIFT" in order to provide fast and accurate GRB positions to ground-based and space facilities, thanks to the combined use of ECLAIRs and 2 narrow-field instruments covering the Xrays and the optical. Within this strategy, ECLAIRs will play a key role since it is the instrument responsible for the detection and the first localization of GRBs in near real time. One of the primary goals of the mission is to study high redshift (z>6) GRBs that may appear as very soft events in Gamma-rays. For this reason, ECLAIRs is designed to have an increased sensitivity in the X-rays, when compared to previous equivalent instruments, thanks to a low energy threshold of 4 keV. In this talk we present the latest developments of the ECLAIRs design along with the expected scientific performances.