Technological development and AIT/AIV activities on ECLAIRs camera onboard the SVOM space mission

ECLAIRs is a hard X-ray telescope onboard the Sino-French SVOM space mission using 2-D coded-mask imaging to detect and localize gamma-ray bursts in the 4-150 keV energy range. Its design is driven by the central objective of achieving a low-energy threshold of 4 keV. The camera is made of 6400 Schottky CdTe detectors organized in 200 hybrid matrices of 4x8 pixels. The detectors are polarized nominally at -300 V and cooled at -20°C to minimize both the leakage current and the polarization effect. The low-energy threshold homogeneity required for the detection plane has been achieved thanks to an extensive characterization of the innovative hybrid module composed of 32 CdTe detectors assembled on a thick film ceramic, associated to an HTCC technology housing a very low-noise 32-channel ASIC chip.

We describe the ECLAIRs instrument, focusing on its different subsystems and the Integration / Tests / Validation activities of the proto-flight camera. We present the different steps of integration and testing with the main results obtained at each step. The main difficulty was to obtain a homogenous detection plane with the best performance and reliability. All these activities were executed on a very short planning with challenging technical requirements (the low-energy threshold of 4 keV). Thanks to our rigorous integration and tests plan, we have performed, in time, the assembly of the complete detection plane and its readout electronics. At the end, the calibration and environmental testing show very good performances for 99.9% of the 6400 detectors.