Physics Requirements for LCLS Endstations

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Physics Requirements for LCLS Endstations

J.B. Hastings
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From the LCLS Global Requirements document
The Project scope includes ? facilities for
production and transport of a bright,
high-current electron beam ? an undulator system
in which the electron beam will generate the
x-ray beam ? facilities for transport,
diagnostics and optical manipulation of the x-ray
beam ? endstations and related facilities for
x-ray experiments ? conventional facilities for
the accelerator systems and x-ray experiments ? a
central lab office building to house support
staff and researchers
This talk will elaborate on the physics basis for
the specification of the LCLS Endstations
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Where the Endstation systems are located
Near Expt Hall
Far Expt Hall
250 m
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Endstation System Overview

• Provides infrastructure for the LCLS experimental
  program
• Hutch systems
• Network and controls
• Synchronized Pump Lasers
• Prototype 2-d detector
• Initial AMO experiment

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Hutch systems

• PPS-Radiation safety for 6 hutches (3 NEH 3 FEH)
• Independent access at all times is desireable
• MPS for single pulse damage threshold
• Provide beam containment system as needed
• ALL systems must be approved by the appropriate
  SLAC safety committees

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Network and Controls

• Expected data rates of 50-100 MB/sec
• Storage, data transfer and computation
  capabilities for this data rate.
• Offsite secure access is required
• 20 workstations per experiment can be expected
  (based on SPPS experience)

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Beamline Controls

• Typically 100 independent motions
• Laser optics
• Sample manipulation
• Angular variables for typical scattering
  experiments
• Automated sample exchange
• EPICS based system is preferred because interface
  between experiments and FELis CRITICAL

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Pump Lasers

• Pump-probe experiments will require
• Synchronised lasers
• 30 fs pulse length
• 800 nm nominal wavelength
• 1 khz repetition rate
• 1 mJ pulse energy
• Timing jitter diagnostics

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Prototype 2-d Detector

• The LCLS provides enough photons per pulse to
  produce complete diffraction patterns
• This requires detectors capable of
• 120 hz read out
• Good DQE gt 50 at 8 keV
• Dynamic range 103
• 1 photon sensitivity
• Pixel size 100-200 microns, smaller may be
  desirable
• Area gt 500 x 500 pixels

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Initial AMO Experiment

• AMO Advisory committee
• Lous F. DiMauro (BNL-Chair)
• Philip Bucksbaum (Univ. Michigan)
• Todd Ditmire (Univ. Texas-Austin)
• Gerhard Paulus (Texas AM)
• Linda Young (ANL)
• Proposed tier I and tier II experiments
• Tier I should be part of LCLS baseline

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Initial AMO Experiments Tier I

• What everyone one wants to know LCLS is in a
  new regime in light-matter interactions
• Atomic absorption Inner shell processes
• Probe complex electron behavior Reaction
  Microscope
• X-ray driven explosions of atomic clusters

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Summary

• Endstation systems will provide
• Complete infrastructure for the LCLS experimental
  program
• Synchronized lasers for laser pump-x-ray probe
  experiments
• A prototype 2-d detector for scattering
  experiments pump-probe
• Initial AMO experiments