Femtosecond Timing Distribution and Control for Next Generation Accelerators and Light Sources

Long term stable and cost effective distribution of precision timing signals with better than 100-fs precision has been a challenging task for many years in fundamental and applied science. With the dawn of fourth generation light sources, such as seeded X-ray Free Electron Lasers (X-FEL), which are currently in design and construction in the US and around the world femtosecond timing distribution has become an urgent need. Next generation light sources will generate, and in fact are already generating at FLASH, DESY, 10-fs EUV and later hard X-ray pulses that can be used to study a variety of scientific topics ranging from condensed matter physics, material sciences, and femtochemistry to studying the structure and function of large biomolecules, one of the holy grails in biophysics. It is obvious that such a facility will operate using the most advanced ultrashort pulse laser and accelerator technology available. Maximum performance of the facility can only be achieved if both the optical and radio-frequency driven sub-components are synchronized to each other with at first a few tens of femtosecond, but ultimately sub-femtosecond precision over extended durations (>24 hours). Commercial Applications and Other Benefits: The objective of the proposed work is to study the feasibility and identify the best approach towards developing a modular femtosecond timing distribution system for next generation accelerators and light sources. Finally, the necessary technology will be transferred from a university laboratory to a small business to make it available for the forthcoming DOE facilities. Key focus of such a system is long-term performance, i.e. timing stability must be maintained over at least 24 hours. The resulting timing distribution system must be scalable in terms of its precision and length, i.e. from the tens of femtoseconds needed today to sub-femtosecond precision over kilometers if distance in the future, cost efficient and robust.