THESEUS is a satellite for the study of high energy transients recently preselected by the European Space Agency for a possible launch in 2032. THESEUS is designed to explore the early Universe through the detection and characterization of a large number of high-redshift gamma-ray bursts and to carry out a monitoring with high-sensitivity of galactic and extragalactic X-ray sources of different classes. Thanks to the high sensitivity and wide field of view of the X-ray ”Lobster eye” instrument (SXI) and of the coded mask gamma-ray telescope (XGIS), coupled to a 0.7m infrared telescope (IRT), and to the rapid repointing capability of the satellite, THESEUS will also greatly contribute to multi-messenger astronomy revealing the counterparts of gravitational waves and high-energy neutrinos.
IASF-Milano is primarily involved in the XGIS gamma-ray instrument, with the responsibility of the GRB triggering and localization system with coded mask imaging, as well as in the design of the electronics for the XGIS detection modules based on scintillators coupled to silcon drift diodes.