1. Identify the properties of future light sources that will be required to help accomplish the scientific challenges described in previous workshops on Basic Research Needs and Grand Challenges. Consider the following “photon attributes” Energy range (from vacuum UV to hard X-rays) Coherence (both transversal and longitudinal) Intensity (photons per pulse and photons per second) Brightness (ultrahigh brightness + low electron emittance) Temporal structure (nano- to attoseconds) Charge 3 from BESAC to the New Era Committee

2. Identify connections between major new research oppor- tunities and the capabilities of the next generation light sources. Find “killer applications” in basic energy research. Emphasize energy-related research and life sciences. Consider both accelerator-based light sources and novel laser based sources for the VUV to X-ray range. Do not consider the design of the light sources, only the required photon attributes. Strong coupling of theory and experiment Charge to the Participants of the Photon Workshop

3. Program of the Photon Workshop  100 Participants, chaired by W. Eberhardt and F. J. Himpsel 2 Overview talks Energy (Crabtree), Life Sciences (Moffat) 4 Talks on Next Generation Light Sources Free Electron Lasers (Pellegrini) Energy Recovery Linacs (Hofstaetter) High Harmonic Lasers (Sandner) Next Generation Storage Rings (Martensson) 9 Breakout Groups Extensive Discussions, Write-up of Highlights (1½ days)

4. 9 Breakout Groups Coordinator: 1. Nanoscale Electrons and Spins Hermann D ü rr (Berlin) 2. Correlated Electrons Z. X. Shen (Stanford) 3. Catalysis and Chemistry Robert Schl ö gl (FHI Berlin) 4. Nano-Materials for Energy Applications Rick Osgood (Columbia) 5. Life Sciences Janos Kirz (Berkeley) 6. Atomic and Molecular Physics Nora Berrah (Western Michigan) 7a. Matter under Extreme Environments Rus Hemley (Carnegie Inst., DC) 7b. Environmental Science, Earth Science Gordon Brown (Stanford) 8. Novel Structural and Electronic Materials Julia Phillips (Sandia) 9. Cross-Cutting Issues John Hemminger (Irvine) Generated ~80 pages describing key scientific opportunities ( “ killer apps ” )

5. Findings 5 Cross-Cutting Challenges 1.Designing Materials and Controlling Processes : The Synthesis-Analysis-Prediction-Loop 2.Real Time Evolution of Electrons, Spins, and (Bio-)Chemical Reactions 3.Single Nano-Objects 4.Statistical Laws of Complex Systems 5.Small and Fast A B C

6. Three Challenges for Future Light Sources Group A: Widest range of applications, largest user community Least aggressive in terms of machine requirements (but clearly beyond available light sources) Group B: New types of experiments, demanding a new kind of light source Sizable number of applications Potential to become the centerpiece of next generation light sources Group C: Most aggressive, but also highest risk and lowest number of users

7. 1. Tailored Materials 2. Understanding the Phenomena 3. Physics and Chemistry at the Atomic and Molecular Level 4. Life Sciences, Medical Applications Findings 4 Scientific Themes A substantial number of nuggets with applications in energy and life sciences were developed by the discussion groups and incorporated into the report.

8. Backup Slides

9. Examples of Cross-Cutting Challenges: Group A 1.Designing Materials and Controlling Processes: The Synthesis-Analysis-Prediction-Loop Materials: Complex materials with correlated electrons, operating devices, batteries, supported catalysts, organic conductors for photovoltaics, lighting, quantum-engineered cluster assemblies Interfaces: In-situ, buried, nano-structured, bio-inorganic, sequestration, grain boundaries in solar cells and superconductors, damage in nuclear reactor materials Catalysts: For artificial photosynthesis, splitting water, in realistic situations (presence of gases, liquids) Static measurements (time-resolved in 2, spatially-resolved in 3, both in 5)

10. 2.Real Time Evolution of Electrons, Spins, (Bio-)Chemical Reactions Find efficient and economical ways of harvesting sunlight to produce electrical or chemical forms of energy (photosynthesis, photovoltaics) Reactions at defects (loss of electrons, radiation damage, in real time) Chemical reaction mechanisms in real time Spintronics: How fast can one switch spins Movies of proteins in action 3.Single Nano-Objects Clusters: From an atom to a solid, tailoring new forms of matter Nanocrystals: Beating the size distribution New materials: Find the electronic structure of a small crystallite Large protein assemblies: From proteomics to cells Examples of Cross-Cutting Challenges: Group B

11. 4.Statistical Laws of Complex Systems Fluctuations of floppy spins and soft materials at the nanometer scale Utilize the full coherence and high degeneracy of a laser Utilize a shaped pulse to reach the minimum uncertainty product 5.Small and Fast Resolve the coupled motion of electrons and nuclei Imaging of elementary chemical reactions at the molecular level Electrons travel nanometers in femtoseconds, challenging the limits of combined spatial and temporal resolution Examples of Cross-Cutting Challenges: Group C