john arthur slac
DESCRIPTION
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. - PowerPoint PPT PresentationTRANSCRIPT
John Arthur
September 26, 2005
John ArthurSLAC
LCLS Construction and Science
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John Arthur
September 26, 2005
X-rays have been the most widely-used probe of nano-world structure
visible
x-ray
John Arthur
September 26, 2005
LCLS will enable the study of the dynamics of the nano-world
synchrotron source
new territory
John Arthur
September 26, 2005
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
John Arthur
September 26, 2005
injector
Near Hall
Far Hall
LCLS will use 1 km of the SLAC linac
John Arthur
September 26, 2005
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
John Arthur
September 26, 2005
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
John Arthur
September 26, 2005
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
John Arthur
September 26, 2005
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
John Arthur
September 26, 2005
LCLS – Revised Estimated Cost, ScheduleLCLS – Revised Estimated Cost, Schedule
$315M Total Estimated Cost (includes $59.7M contingency)
$379M Total Project CostFY2005 Long-lead purchases for injector, undulatorFY2006 Construction beginsFY2008 FEL Commissioning begins FY2009 Q2 Construction complete – operations begin – CD-4
2002 2003 2004 2005 2006 FY2008 FY2009
Construction Operation
FY2001 FY2002 FY2003 FY2004 FY2005 FY2006 FY2007
CD-1 CD-2aCD-2b
CD-3a
CD-3bCD-0 Title IDesignComplete
XFELCommissioning
CD-4
Project Engineering Design Long-LeadProcurement
John Arthur
September 26, 2005
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LCLS Science
John Arthur
September 26, 2005
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
John Arthur
September 26, 2005
LCLS Science Thrust Areas
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
After a broad call for proposals in 2004, the LCLS SAC identified:
John Arthur
September 26, 2005
Formation of Hollow Atoms:
h900eVAuger
=2.5fs
Multiphoton Ionization:
h
h
Atomic Physics The interaction of strong x-ray electromagnetic fields with atoms should produce many unusual effects
Normal H wavefunction
H wavefunction in strong x-ray field
John Arthur
September 26, 2005
High Energy-Density Science
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
normal solids
hot plasmas
0 C
10,000 C
100,000,000 C
“warm dense matter”
John Arthur
September 26, 2005
Stimulated Dynamics(Femtosecond Chemistry)
fs laser initiates reaction
Delayed x-ray probe pulsesample
Combine single-pulse x-ray diffraction with fast laser excitation
Studies of small system reactions can be compared with theory
X-ray FEL offers the ability to follow the motions of atoms on a femtosecond time scale
John Arthur
September 26, 2005
Femtosecond Chemistry (cont.)
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.
Ground state Excited state
John Arthur
September 26, 2005
t=0
t=
In picoseconds - milliseconds range
sample
splitter
variable delay Δt
Analyze contrastas f(delay time)
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
John Arthur
September 26, 2005
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
John Arthur
September 26, 2005
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)
John Arthur
September 26, 2005
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
John Arthur
September 26, 2005
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