NEH 1.1 or Time-resolved AMO (TMO)

TMO or NEH 1.1

NEH beamline 1.1 will support many experimental techniques not currently available at LCLS. High operational efficiency will be achieved through utilization of multiple fixed endstations. Stable beam trajectories will be provided through streamlined X-ray alignment to the fixed interaction points. Delivering the beam to only a few fixed locations will optimize optical laser experiments and setups.

Both the existing LAMP as well as the newly built DREAM endstation will be configured to take full advantage of both the high per pulse energy from the copper accelerator (120 Hz) as well as high average intensity and high repetition rate from the superconducting accelerator.

Endstation Descriptions

The new DREAM endstation will house a well-defined geometry and COLTRIMS type spectrometer as a standard configuration to accommodate extreme vacuum, sub-micron focus spot size, and target purity requirements dictated by the pump-probe class of coincidence experiments, while accumulating data on the event-by-event basis at the rep rates in excess of 100 kHz fully utilizing the LCLS-II capabilities. Photon fluence in DREAM will reach over 1021 photons/cm2 with superconducting Linac X-rays, while with copper accelerator it will be over 1022 photons/cm2 at 120 Hz.

The current modular and flexible LAMP endstation will be optimized to better perform high energy, high resolution, time-resolved photoelectron spectroscopic measurements. Leveraging its existing suite of established spectrometers such as high resolution iTOF, eTOF, LAMP double-sided VMIs, Kaesdorf spectrometers, a high resolution, high throughput, hemispherical electron analyzer will be permanently installed.

Depending on the photon energy, LAMP X-ray photon fluence goal is in high 1020 photons/cm2 range with superconducting Linac, and high 1021 photons/cm2 range with copper accelerator at 120 Hz.

Pump-probe timing resolution of X-ray with optical laser pulses goal is sub 10 fs for both endstations. Optical laser peak field power density will be over 1015 W/cm2 (of 800 nm) on target.


Parameter  Value 
Undulator Source SXU
Photon Energy Range SXU  250-2500 eV
Focused Beam Diameter SXU (FWHM) ~ 1 μm (LAMP) & ~ 300 nm (DREAM)
X-ray Bandwidth 
  • 3 × 10−3 
  • 1 × 10−4 (seeded) 
Beamline Transmission  > 80% (LAMP) & > 75% (DREAM)
Repetition Rate up to 929 kHz
X-ray Power Limit 200 W
Optical Laser 200 nm to 17 μm with varying power, repetition rate, and pulse duration 
Primary X-ray Techniques
  • Dynamic Molecular Reaction Microscope
  • X-ray Pump / X-ray Probe, Optical pump / X-ray Probe
  • Coherent Forward Scattering, Imaging & Diffraction

Advisory Panel

  • Christoph Bostedt - Argonne
  • James Cryan - SLAC
  • Reinhard Dörner - Frankfurt
  • Oliver Gessner - LBNL - CSD
  • Markus Guehr - U. Potsdam
  • Daniel Rolles - KSU
  • Thorsten Weber - LBNL - CSD
  • Nora Berrah - U. Conn
  • Adrian Cavalieri - MPSD, CFEL, U. Hamburg
  • Jon Marangos - ICL
  • Artem Rudenko - KSU
  • Timur Osipov - SLAC