Speaker
Description
Crystals can channel charged particle beams along major crystallographic directions, providing a compact and efficient tool for beam manipulation at high energies. In bent crystals, channeled particles follow the crystal curvature, enabling beam steering over very short distances. While this technique has been extensively investigated for hadron beam collimation and extraction at the CERN SPS and LHC, as well as at FNAL, its application to electron and positron beams is attracting increasing interest in view of future high-energy lepton accelerators.
For future linear colliders, crystal-based technologies may contribute to several key areas, including beam extraction and manipulation, intense photon generation, and positron production. In oriented crystals, coherent interactions can strongly enhance electromagnetic radiation compared with ordinary bremsstrahlung, enabling compact sources of high-energy photons. Crystalline undulators further extend this concept, offering the possibility of generating hard X-rays and gamma rays at sub-ångström wavelengths through the periodic motion of channeled particles.
A particularly promising application is the use of oriented crystals as photon radiators for high-intensity positron sources, a concept originally proposed by Chehab and Variola and later developed by Chehab, Chaikovska and collaborators for CLIC, with important experimental tests carried out at KEK. The enhanced radiation emission can improve positron production while reducing the energy deposition in the conversion target.
This contribution reviews recent experimental and technological advances in crystal-based beam manipulation and radiation generation, with particular emphasis on their potential applications to future electron–positron linear colliders.