The project intends to develop innovative silicon detectors, highly competitive in detecting photons for precision experiments mainly dedicated to studying X and gamma rays. These detectors have applications in multiple fundamental and applied science fields (particle and astroparticle physics, detectors of synchrotron radiations, medicine, cultural heritage). There are two main areas of development:

- Study of silicon drift detectors (SDD). This branch of the collaboration, established by the INFN Trieste, includes the Polytechnic University of Milan, the FBK Foundation of Trento, Elettra Sincrotrone Trieste and a few components of the INAF.

- Study of avalanche photodiodes or silicon photomultipliers (SiPM). This branch includes, besides the University and the INFN group of Udine, the FBK Foundation of Trento, the INFN groups of Bari, Padua, Perugia, Pisa, Rome “La Sapienza”, Rome Tor Vergata and Trieste.

These activities are performed within the framework of newly designed experiments, mainly intended for space applications or for advanced laboratory applications.

For the purpose of a dissemination in the territory of the themes linked to the research threads for which these detectors are being developed, the project provides for a stage for the production of didactic materials meant for this purpose, both at the level of the secondary schools and of the universities. The preparation of these materials will be an opportunity for didactic innovation based on research (both discipline and educational research).

As to the more properly astrophysical aspect, it should be highlighted that, after the first direct detection of gravitational waves, in the fall of 2015, by the LIGO/Virgo collaboration, a new study field opened, that of gravitational wave astronomy. Even though the events detected this far have always been compatible with black hole fusion phenomena, from which only gravitational waves can be expected to be emitted, the scientific community has liaised, waiting for the detection of the first event in which an electromagnetic counterpart will be present, such as, for instance, in the final phase of the collapse of a system containing two neutron stars or a neutron star and a black hole: in these cases, in fact, an electromagnetic emission is expected in addition to the gravitational one. The detection of an electromagnetic counterpart will allow a more accurate spatial location of the event, the identification of the host galaxy, and the in-depth study of the properties of the surrounding region. Such a complementarity of the gravitational and electromagnetic information favoured the participation of a large number of experimental groups to a project for the electromagnetic follow-up in presence of signals of gravitational waves. The electromagnetic emission is linked with the fact that the acceleration mechanisms of charged particles are extremely efficient when magnetic fields change very rapidly, as is the case with neutron stars. Accelerated charged particles emit photons thanks to many processes: Bremsstrahlung, synchrotron emission associated with on-site magnetic fields, Compton effect on already existing photons, decay of pions coming from the interaction with gases. These processes produce radiations in a wide energy spectrum, depending from the parameter values determining the astrophysical characteristics of the system. This consideration highlights the importance of studying the electromagnetic emission, by means of a synergy of available instruments in different and complementary zones of the energy spectrum. Detectors such as the SDDs and the SiPMs, which this project is referred to, are very promising and innovative both as to sensitivity and speed in the region of the X and gamma rays, in comparison with instruments currently in use. These developments are expected to allow exceptionally relevant results, including for several applications to new experimental areas or already active experiments within the framework of the research activities of the Department.