SCLF Science Considerations for Discussion Science priorities should be based on compelling open science questions that can only be answered with the distinguishing capabilities of SCLF (i.e. high rep rate soft and/or hard X-rays) Why is this science opportunity (research thrust/area) important, and what will be the broad impact when this question is answered? Why is this a critical next step to advance this area of science, and why is SCLF essential? Consider projected state of scientific knowledge and technical capabilities in the near future What science questions are likely to be answered (or significantly advanced) in the next seven years? To what extent should SCLF focus on science that might be accomplished at other XFELs (e.g. low rep rate facilities)? – What is the proper balance? Consider capacity needs, support for local and/or national science programs and priorities etc. What are the most compelling science opportunities (that require the unique capabilities of SCLF) in specific areas, e.g.: AMO & gas phase chemistry Coordination chemistry, photo-catalysis, catalysis Materials Physics HEDS SCLF should consider organizing and leading collaborative teams of experts for early science What is the best approach/structure for accomplishing this? How can advisory panels (or some sort of peer-review) help guide this process? How can SCLF capitalize on the strongest local talent and science programs in this process? This process should help refine the detailed instrument specs and diagnostics requirements for early science Quantum Materials Biology other….

SCLF Instrumentation Considerations for Discussion Scientific impact and early success of SCLF Instrumentation should be defined by specific scientific needs (target experiments) Instrumentation plans should be sufficiently flexible to take advantage of scientific and technical developments in the near future Consider projected advances in technical capabilities in the near future Where will the competition be (both X-ray and non X-ray approaches) in seven years? e.g. cryo-EM, table-top laser ARPES, DLSRs, HHG/atto etc. What are the projected development paths for: Detectors Lasers Data science and novel analysis methods X-ray optics Novel XFEL capabilities (seeding, multi-pulse, multi-color, atto-pulses etc.) Where are the gaps in capabilities, instrumentation, or methods that might require R&D? i.e. what targeted R&D or methods development by SCLF might have the greatest scientific impact?