Study of channeling phenomena in bent crystals: the new frontiers

More or less 30 years ago, it was experimentally demonstrated how a bent crystal can become a magnet: an object 1 mm thick, a couple of mm wide and a few cm high is, in fact, capable of steering particles as a dipole of several tens of Tesla. Exploiting this feature, from September 2006 the H8RD22 collaboration is testing several bent crystals in order to develop a crystal based collimation system for LHC: in very high energy accelerators, in fact, the typical multi-stage collimation system (that must be very efficient and must tolerate very high radiation) is expected not to allow to reach the nominal luminosity, limiting it to 40% of the desired value. A bent crystal could play a key role being a clever collimator: it is able to steer particles in a given direction with a high efficiency, thus increasing the cleaning efficiency, reducing the constraints on the alignment of the secondary collimator and finally increasing luminosity. But bent crystals are not only collimation: the radiation emitted by light particles in such crystals could be a real breakthrough for several applications, from the the generation of intense gamma beams for a positron source to the collimation of electron-positron beams at the future linear collider. This study is still an open field, given the constraints on the beam and on the experimental setup. The goal of this thesis work is to give an insight of the physics of bent crystals from several poin ts of view: their behavior with heavy and light particles, the possible applications in different fields and the experimental results obtained in recent beam tests with 400 GeV/c and 180 GeV/c heavy and light particles.