Compact X-band accelerator technology for linear colliders

Linear Colliders are candidates for the next generation of particle colliders for high energy physics, which will complement the LHC-results. In order to achieve enough collisions per second to perform precision physics, the electron and positron beams c olliding must be of unprecedented high quality, with an ultra small emittance. This project further develops emittance preservation schemes for linear colliders, including experimental tests of beam based alignment schemes and design of wake field monito rs for micrometer alignment of the beam inside accelerating structures. The project also studies how the high-gradient CLIC X-band rf technology can be used for cost-effective, compact Free Electron Lasers. Finally, the project also studies emittance preservation for plasma based accelerators. We have experimentally tested different operational modes of wake field monitors, and also developed new methods for emittance preservation by theory and numerical simulations. We have furthermore studied emittance preservation in plasma lenses, both numerically and experimentally. This work has lead through new results on the possibility of emittance preservation in plasma accelerators. Both the experimental and the numerical developments are important steps for emittance preservation strategies for future colliders

We set out to study emittance preservation in linear colliders. As the publication list demonstrates, the research performed has contributed significantly to understand the potential for emittance preservation in linear colliders, including for colliders where plasma technology may be used to improve performance. The research has also been presented to the general public in various forms, with emphasis on illustrating the usefulness and need for particle accelerators in the society.

CLIC is developing compact X-band high-gradient accelerator technology in order to push the linear collider energy reach into the Multi-TeV range. One of the main challenges for a linear collider is to preserve nm level beam emittances during the accelera tion process, which is necessary to reach the luminosity required for the physics studied. A key component of CLIC's emittance preservation scheme is precision wake field monitors, mounted on the accelerating structures. We propose to take the lead in the developments of the wake field monitors, including detailed microwave design, prototyping of read-out electronics, experimental tests with an electron beam in CTF3 and simulation studies of the emittance preservation in the CLIC main linac. The proposed project will include a post.doc. researcher to lead the design and experimental tests and a PhD student to exploit the experimental test results to study the feasibility of emittance preservation in CLIC using wake field monitors. In the CLIC project othe r applications for CLIC X-band technology are currently being studied, in particular applications to compact hadron-therapy machines and compact Free Electron Lasers. As a secondary activity in this project, we will participate in the X-band technology a pplication studies focusing on applicability to future Norwegian projects.