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LCLS Construction and Science. John Arthur SLAC. X-rays have been the most widely-used probe of nano-world structure. visible. x-ray. LCLS will enable the study of the dynamics of the nano-world. synchrotron source. new territory. Key features of LCLS X-Ray FEL Radiation.
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LCLS Construction and Science John Arthur SLAC
X-rays have been the most widely-used probe of nano-world structure visible x-ray
LCLS will enable the study of the dynamics of the nano-world synchrotron source new territory
Key features of LCLS X-Ray FEL Radiation • Sub-picosecond pulse • 230 fs FWHM pulse (ultimately < 10 fs) • Very high peak power and brightness • More than 1012 photons/pulse
LCLS will use 1 km of the SLAC linac injector Near Hall Far Hall
Major LCLS Construction Areas • Linac Sector 20: LCLS injector • Beam Transport Hall across Research Yard • Undulator Hall under survey tower • Near Exptl Hall and Central Lab Office Complex near PEP road • X-ray Transport Hall underground • Far Experimental Hall underground
LCLS Injector and Linac modifications • Injector construction underway • Begin commissioning spring/summer 2006 • Linac mods during FY05, FY06 downtime • No interruption of linac schedule, but FY06 downtime is critical
Research Yard construction • Will begin early summer 2006 • Begin with demolition of FFTB • Will permanently divide Research Yard in two • Road over survey hill will be improved • Construction will continue through 2008
Underground construction • Will begin summer 2006 • Will often interrupt the PEP road • Will utilize the Alpine gate as construction entrance • Ways to minimize disruption being evaluated • Will continue through 2008
2002 FY2001 2003 FY2002 2004 FY2003 2005 FY2004 FY2005 2006 FY2008 FY2006 FY2009 FY2007 LCLS – Revised Estimated Cost, Schedule • $315M Total Estimated Cost (includes $59.7M contingency) • $379M Total Project Cost • FY2005 Long-lead purchases for injector, undulator • FY2006 Construction begins • FY2008 FEL Commissioning begins • FY2009 Q2 Construction complete – operations begin – CD-4 CD-2b XFEL Commissioning CD-1 CD-2a Title I Design Complete CD-0 CD-3b Project Engineering Design Long-Lead Procurement CD-3a CD-4
LCLS will be operated as a user facility by the SLAC Photon Science Division, for the DOE Office of Basic Energy Sciences • If funding permits, ~6000 hr/year operation • Science program will be flexible; initial concepts being developed now with advice from LCLS Science Advisory Committee
LCLS Science Thrust Areas After a broad call for proposals in 2004, the LCLS SAC identified: • Atomic, Molecular, and Optical (AMO) science • High-energy-density (HED) science • Diffraction studies of stimulated dynamics • Coherent-scattering studies of nanoscale fluctuations • Nano-particle and single-molecule (non-periodic) imaging
Formation of Hollow Atoms: hn =900eV tAuger =2.5fs Multiphoton Ionization: hn hn The interaction of strong x-ray electromagnetic fields with atoms should produce many unusual effects Atomic Physics Normal H wavefunction H wavefunction in strong x-ray field
High Energy-Density Science 100,000,000 C hot plasmas “warm dense matter” 10,000 C normal solids 0 C Astrophysical and weapons-related studies lie in the area of warm dense matter. Largest uncertainties in many applied research areas of chemistry and physics come in the warm dense regime
Stimulated Dynamics (Femtosecond Chemistry) X-ray FEL offers the ability to follow the motions of atoms on a femtosecond time scale Studies of small system reactions can be compared with theory Combine single-pulse x-ray diffraction with fast laser excitation Delayed x-ray probe pulse sample fs laser initiates reaction
Femtosecond Chemistry (cont.) Ground state Excited state Electronic excitation of a bridged bimetallic complex causes bond length shortening and rotation. These excited state molecules can catalyze a variety of chemical reaction including H2 production.
t= t=0 splitter Nanoscale Dynamics in Condensed Matter (Dynamics of large groups of atoms) Look at equilibrium dynamics in solids and liquids, by taking a succession of flash images In picoseconds - milliseconds range sample variable delay Analyze contrast as f(delay time)
X-Ray Diffraction from a Single Molecule or Nano-particle Avoids radiation damage problem by taking diffraction data before damage occurs Would allow much broader range of biological structures to be determined
BES funding for the Thrust Areas • AMO science is included in LCLS construction project • HED science deemed to be outside the mission of BES • Probably will be funded by another agency • 3 other Thrust Areas funded through a new project called “LCLS Ultrafast Science Instruments” (LUSI)
Development of an LCLS science community • Through many workshops since 1992, the LCLS science community is already large and active (>150 people) • LCLS SAC meets semiannually at SLAC • 5 Thrust Areas have identified spokespeople, who have quarterly meetings at SLAC • Plan is to have yearly general meetings of LCLS science community • New ideas are always welcome
LCLS Summary • LCLS design is nearly complete, construction is starting • Budget is adequate and DOE has been very supportive • First light expected in late 2008 • LCLS will enable qualitatively new types of science • The science program will evolve as experience is gained