These are discussion agenda during Working Group discussion time.
If you have materials to present for sake of discussion, please prepare them (a few slides) prior to the workshop.
WG-A: Linac-Based Light Sources
1.What are the optimization strategies used in tuning a single pass, linac based FEL for user operation ?
2. Will artificial intelligence play a role in tuning and optimizing FEL sources ?
3. Will artificial intelligence play a role in tuning and optimizing FEL sources ?
4. What are the ultimate challenges and limitation in simultaneously serving multiple beamlines in FEL facilities?
5. Can we start thinking to experiments with multiple FEL pulses from independent FEL lines ?
6. What are the main challenges and desiderata in the generation of ultrashort pulses in FELs ?
7. What are the strategies for temporal synchronization of ultrashort (sub-fs) FEL pulses
8. Seeded FELs have many nice properties with respect to SASE sources, as improved stability and longitudinal coherence. What are the available options to extend the wavelength range of seeded FELs to shorter wavelengths, covering the soft and hard X-ray spectral range ?
9. What are the main differences between self-seeding and external seeding from the point of view of the light properties
10. What are the main challenges in the understanding and mitigating the microbunching instability in linac based accelerators ?
11. How well do the present simulations codes reproduce the detailed FEL performance?
12. What be included in the ideal FEL simulation code suite?
WG-B: Ring-Based Light Sources
1.Are there new ideas for storage ring lattices that could go beyond currently-envisioned MBA lattices?
2. Should we be making more use of permanent- or superconducting-magnet technologies?
3. Should new facilities plan for a full-energy linac injector to allow pushing the ring as far as possible?
4. How can we make short lifetimes workable, so we can continue pushing the emittance down?
What theory and code developments do we need to ensure that next-generation rings work as planned?
5. What experiments can be performed on existing rings to remove uncertainties for next-generation rings?
6. Besides rings optimized for ultra-high-brightness, what other types of rings should we be designing?
7. What's needed to make first-principles impedance models more accurate in predicting instabilities?
8. What commissioning strategies are best for next-generation rings?
9. How do storage ring design and beamline design interact; e.g., round vs flat beams, tailoring of beta functions vs lowest emittance?
10. Can ultra-bright rings also provide short pulses?
11. Is low emittance more demanding of insertion device quality, e.g., phase errors?
12. Are there new beam stability challenges and what are the best ways to address these?
WG-C: Compact Light Sources
1. What's the main challenges of laser driven plasma wakefield accelerator for FEL applications?
2. What's the main challenges of beam driven plasma wakefield accelerator and beam driven structure wakefield accelerator for FEL applications?
3. Road map of Wake Field accelerator based FELs and current position.
4. How can the key FEL elements (like undulator, timing control, etc) be more tolerable to the new accelerator schemes?
5. Shall we consider efficiency of the overall facility? And how to improve it?
6. Comparison of new concept linac based with the ring based FEL.
7. Comparison of non-FEL sources (Compton & HHG) and future compact X-FELs.
8. Comparison of Compact sources to synchrotron radiation.
9. Comparison with advanced acceleration schemes with high gradient conventional accelerator approaches
compact infra red sources.
WG-D: Key Technologies
1. What is more important for the future light sources, better resolution or higher data rate? What are challenges of bunch position and length monitors?
2. What are challenges for X-ray position and electron emittance monitors? Are intra-bunch instability (e.g. microwave/CSR) monitors needed and do they need further development?
3. Magnets technologies for low emittance lattices and combined function magnets, new developments, future directions
4.What are the challenges and technologies for future LER very high gradient and small aperture magnets? Are completely PM magnets viable? What is future of SSAs for normal conducting RF systems? Are fast kicker pulsers available commercially for most applications? Should LLRF design be standardized?
5. New concepts/ technology for short period undulators for use in high duty cycle FELs
Achievements and comparison of peak field vs period length of PM/cryogenic with SC undulators. State of the art to achieve highest fields ? Nb3Sn / high TC superconductors
State of technological development to build large undulator systems (with Quadrupoles, Phase shifters, BPMs correctors etc. ) for use in future light sources such as LCLSII Upgrade, the Chinese XFEL or a European XFEL CW upgrade.
6. Radiation damage in SC undulators, comparison of SC vs PM. Best technology for use in a harsh radiation environment such as high duty cycle linacs.