TMO - Time-resolved AMO


The Time-resolved atomic, Molecular and Optical Science (TMO) instrument, one of the three new LCLS-II instruments with a energy range from 0.25 to 2 keV, will support AMO science, strong-field and nonlinear science, and a new dynamic reaction microscope. TMO will support many experimental techniques not currently available at LCLS and will have two X-ray focus spots. The NEH beamline 1.1  science end station, 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 (1 MHz) from the superconducting accelerator. TMO will have two X-ray beam focus spots. 

Endstation Descriptions

The first TMO focus spot will be the Next generation Atomic, Molecular, and Accelerator Science and Technology Experiments (NAMASTE) and it will be optimized for performing high energy, high resolution, time-but also angular-resolved photoelectron spectroscopic measurements. It will accept highly standardized modular endstations. Depending on the photon energy, NAMSTE X-ray photon fluence goal is in high 1019 photons/cm2 range with superconducting Linac, and high 1020 photons/cm2 range with copper accelerator at 120 Hz.

The second TMO focus spot will be the new Dynamic REAction Microscop (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.

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   250-2000 eV
Focused Beam Diameter (FWHM) < 1.5 μm (NAMASTE) & < 300 nm (DREAM)
X-ray Bandwidth 
  • 3 × 10−3 
  • 1 × 10−4 (seeded) 
Beamline Transmission  ~ 80% (NAMASTE) & ~ 60% (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
  • two bunch / two color

Advisory Panel

  • Christoph Bostedt - PSI, ETH Zurich
  • James Cryan - SLAC
  • Reinhard Dörner - Frankfurt
  • Gilles Doumy – Argonne
  • 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