Office of Basic Energy Sciences Office of Science
Office of Basic Energy Sciences Office of Science, U. S. Department of Energy Linac Coherent Light Source Update Eric A. Rohlfing BESAC Meeting February 26, 2001 Basic Energy Sciences Atomic, Molecular & Optical Sciences Fundamental Interactions Team Chemical Sciences, Geosciences, and Biosciences Division
Scientific Case for the LCLS u “LCLS: The First Experiments” Scientific case directly tied to decision on proceeding with LCLS construction (Critical Decision 0 - Conceptual Design) Aimed at defining (in some detail) the first classes of experiments that would be mounted on the LCLS Basis for experimental requirements for the LCLS CDR Assembled through the LCLS Scientific Advisory Committee u Reviews Presented to and discussed by BESAC in October Unanimous vote to recommend that BES approve CD 0, contingent upon positive external peer review External peer review completed in November - 13 reviews (out of 20 contacted) Basic Energy Sciences Atomic, Molecular & Optical Sciences Fundamental Interactions Team Chemical Sciences, Geosciences, and Biosciences Division
Reviewers Comments u General Very similar to BESAC comments and generally positive Several reviewers noted significant improvement over earlier efforts Tendency for reviewers to favor science outside their area of expertise u Specific Areas: (1) Atomic Physics Agreed that these studies are basis for understanding intense x-ray-matter interactions Criticized for not being innovative; concern about lack of impact on field Concern over interpretation of nonlinear processes with spiked temporal structure (lack of longitudinal coherence) in LCLS pulses Basic Energy Sciences Atomic, Molecular & Optical Sciences Fundamental Interactions Team Chemical Sciences, Geosciences, and Biosciences Division
Reviewers Comments u Specific Areas: (2) Plasma and Warm Dense Matter Clear niche role for LCLS, particularly as a pump source to create WDM Concern over broader impact and relevancy to BES, but noted clear relevancy to DOE Defense Programs (3) Structural Studies on Single Particles and Biomolecules Most positive set of comments; clearly at forefront of field with huge potential impact But, some skepticism, not concerning damage model, but whethere would be sufficient signal-to-background to extract molecular structure information Basic Energy Sciences Atomic, Molecular & Optical Sciences Fundamental Interactions Team Chemical Sciences, Geosciences, and Biosciences Division
Reviewers Comments u Specific Areas: (4) Femtochemistry Weakest set of reviews from those most directly associated with ultrafast dynamics (stronger from those outside) Concerns with synchronization between laser pump and LCLS probe Clear need for shorter pulses in order to have real impact in dynamics, particularly in the gas phase (5) Studies of Nanoscale Dynamics in Condensed Matter Physics Few review comments (little thin on reviewers) Not clear that LCLS parameters are ideally suited to experiments; damage calculations for XPCS look marginal Basic Energy Sciences Atomic, Molecular & Optical Sciences Fundamental Interactions Team Chemical Sciences, Geosciences, and Biosciences Division
Reviewers Comments u Specific Areas: (6) X-ray Laser Physics Few comments (again a bit thin on reviewers) Strongly endorsed attempts to shorten LCLS pulse based on scientific needs, particularly for Femotchemistry Basic Energy Sciences Atomic, Molecular & Optical Sciences Fundamental Interactions Team Chemical Sciences, Geosciences, and Biosciences Division
Path Forward u BES has delayed approval of CD 0 Strong support for the LCLS project, but…. Scientific case and level of “community” support not yet sufficient BES Workshop on Scientific Applications of Ultrafast, Intense, Coherent X-Rays u Organizers: Eric Rohlfing and Pedro Montano, BES Focus: scientific applications of source with LCLS specifications with emphasis on ultrafast dynamics, nonlinear optics, x-ray imaging Participants: 20 -25 scientists; LCLS “veterans” with newcomers Logistics: May 4 -5, 2001; Wardman Park Marriott, Washington, DC Output: report that complements and broadens LCLS scientific case Basic Energy Sciences Atomic, Molecular & Optical Sciences Fundamental Interactions Team Chemical Sciences, Geosciences, and Biosciences Division
BES Vision for the LCLS is partly an accelerator/FEL R&D project, but it must also be. . u u A stand-alone scientific user facility The LCLS is not a step along a predetermined path toward a larger XFEL facility u Basic Energy Sciences Atomic, Molecular & Optical Sciences Fundamental Interactions Team Chemical Sciences, Geosciences, and Biosciences Division
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