# Future Perspectives for Gamma-ray Burst Detection from Space
## 11 Svom
### Instrument Design  
ECLAIRs is a coded-mask telescope, composed of a 54 \(\times\) 54 cm\({}^{2}\) pseudo-random coded mask made of a Ti-Ta-Ti sandwich (10/0.6/10 mm) placed 45.8 cm above a pixelated detection plane made of 80 \(\times\) 80 CdTe crystals (4 \(\times\) 4 \(\times\) 1 mm\({}^{3}\)). Its FoV is about 2 sr (89\({}^{\circ}\)\(\times\) 89\({}^{\circ}\)) wide. ECLAIRs is sensitive in the 4 keV-150 keV energy range, and it comprises on-board software to detect and localize (to better than 13 arcmin) in near-real time the GRBs that appear in its FoV. Once a new transient is detected, ECLAIRs issues an alert and requests the platform to slew so that the error box can be observed by the narrow-field instruments.  
ECLAIRs is complemented by the Gamma-ray Monitor (GRM), a set of three 1.5 cm thick NaI scintillators of 16 cm in diameter, each one offset by 120\({}^{\circ}\) with respect to each other and with a combined FoV of \(\sim\)2.6 sr. The GRM has poor localization capabilities, but it extends the SVOM spectral range up to about 5 MeV and increases the probability of the simultaneous detection of short GRBs and GW alerts.  
The Microchannel X-ray Telescope is a light (\(<\)42 kg) and compact (focal length of \(\sim\)1.15 m) X-ray-focusing telescope; its sensitivity below 1 mCrab makes it the ideal instrument to detect, identify, and localize down to the arcmin level X-ray afterglows of the SVOM GRBs. Its optical design is based on a \"lobster-eye\" grazing-incidence X-ray optics, inspired by the vision of some crustacean decapods. It is composed of 25 square MPO plates of 40 mm each arranged in a 5 \(\times\) 5 configuration. Although lobster-eye optics were originally developed for large-FoV telescopes (several tens of square degrees), the MXT optical design is optimized for a (relatively) small FoV of 58 \(\times\) 58 arcmin\({}^{2}\). The \"lobster-eye\" technique results in a peculiar point-spread function (PSF), made by a central peak and two cross-arms. The MXT optics is coupled with a focal plane based on a pnCCD sensor, cooled at -65\({}^{\circ}\), sensitive in the 0.2-10 keV energy band. The MXT will localize GRB afterglows to better than the arcminute for the majority of them.  
The Visible Telescope (VT) is a Ritchey-Chretien telescope with a 40 cm diameter primary mirror. Its field of view is 26 \(\times\) 26 arcmin\({}^{2}\) wide, adapted to cover the ECLAIRs error box in most of the cases. It has two channels, a blue one (400-650 nm) and a red one (650-1000 nm), and a sensitivity limit of \(M_{V}\) = 22.5 in 300 s, allowing the detection \(\sim\)80% of the ECLAIRs GRBs. The main characteristics of the SVOM space segment are summarized in Table 3.  
Figure 19: The fully integrated SVOM payload.  
The SVOM mission is also provided with a number of dedicated telescopes on the ground. In particular, here, we mention the following:  
* The Ground-Based Wide-Angle Cameras (GWACs), a set of 36 optical cameras with a combined FoV of 5400 deg\({}^{2}\), located in Ali (China), whose goal is to catch the prompt optical emission for the ECLAIRs GRBs;
* The Chinese Ground Follow-up Telescope (C-GFT), a robotic 1 m class telescope, with a 21 \(\times\) 21 arcmin\({}^{2}\) FoV, located in Xinglog (China) and sensitive in the 400-950 nm wavelength range;
* The French Ground Follow-up Telescope (F-GFT, Colibri), a robotic 1 m class telescope, with a 26 \(\times\) 26 arc min\({}^{2}\) FoV, located in San Pedro Martir (Mexico) and with multi-band photometry capabilities over the 400-1700 nm wavelength range.  
Other robotic telescopes will be part of the SVOM follow-up system, but they will not be fully dedicated to SVOM.