TMO Standard Configurations for Run 22
The Time-resolved Atomic, Molecular and Optical Science instrument (TMO) will support a wide range of science including gas phase photochemistry, attosecond electron dynamics, and the study of complex systems at the nanoscale. This includes the use of nonlinear and strong-field X-ray processes. The instrument features two interaction points appropriately named interaction point 1 (IP1) and interaction point 2 (IP2). TMO makes use of the LCLS soft X-ray undulators, providing horizontally polarized X-rays in the photon energy range from 250 eV to 1800 eV. During Run 22 TMO will offer two different end stations, the magnetic bottle time-of-flight electron spectrometer (MBES) and angle-resolving electron time-of-flight spectrometer (MRCO), in the first interaction point (IP1). During Run 22 we also plan to continue the commissioning efforts of the DREAM end station at IP2, to have this instrument ready for Users in Run 23.
Key Performance Parameters for Run 22
Run 22 will be the first opportunity to make use of the new superconducting LCLS-II accelerator which will eventually operate at repetition rates up to 1 MHz. During the first run the repetition rate will be limited to 100 kHz with the following X-ray performance parameters. Please direct any questions on X-ray parameters to James Cryan (email@example.com).
Repetition rate (Hz)
Up to 100 kHz
Energy Range (eV)
250 - 1800
20 fs (nominal)
Expected Development (increased risk)
Tunable to 5 fs
< 1 fs (XLEAP-II)
Energy per pulse
~ 50 µJ
Scales linear with
Spot Size, FWHM (range)
1.0 - 200 um diameter
Two Pulse Mode
< 10 µJ / pulse with tunable delay via split undulator method.
The new OPCPA laser system should offer short (< 25 fs) 800 nm laser pulses. Harmonics of these pulses can be generated (400/266 nm). The generation of 266 nm pulses at high repetition rate presents many technical challenges and is still under development.
Repetition rate (Hz)
Synchronized up to 33 kHz
< 25 fs
< 30 fs
~ 30 fs
< 100 fs
Energy per pulse (on target)
< 600 µJ
< 100 µJ
~ 10 µJ
< 130 µJ (signal)
Spot Size, FWHM (800 nm)
50 to 100 um
Variable: linear, circular
~0.5o angle with X-ray beam
Arrival Time Monitor
< 20 fs accuracy in X-ray/laser arrival time tagging should be available. Overall temporal resolution will be dependent on machine and instrument configuration
TMO Spectrometers for Run 22 Standard Configuration
For more information, please contact James Cryan (firstname.lastname@example.org).
MBES: Magnetic Bottle Electron Time-of-Flight Spectrometer in IP1
For Run 22 TMO will provide a magnetic bottle electron spectrometer. The spectrometer is coupled to a dual anode micro-channel plate detector allowing for some radial-discrmination of the measured spectrum.
The endstation features:
- Gas targets:
- Either heated gas needle or
- In-vacuum oven
- 2m flight tube with retardation section, >50% collection efficiency
- Resolution DE/E <5%
- Retardation up to 200 eV
- Ion extraction plate and coincident Ion ToF capability
- Currently under development, this capability is offered at risk.
MRCO: Angle-resolving Electron Time-of-Flight Detector in IP1
In Run 22 TMO will provide and angular array of electron time-of-flight spectrometers offering high energy- and angular-resolution for electorn spectroscopy. This endstation features:
- Gas targets:
- Heated gas needle
- 8-16 eToF spectrometers, ~1% total collection efficiency
- Resolution DE/E < 1%
- Retardation up to 2000 eV
- Angular Acceptance 1.5o - 3.0o per ToF
- 8 ToFs guaranteed, additional ToFs are planned.
Photon Spectrometer Diagnostic
In Run 22 we will offer a photon spectral diagnostic downstream of IP1. This device uses an off-axis Fresnel Zone-Plate (FZP) to spectrally disperse the incident X-ray onto a high repetition rate detector. A line-scan camera at maximum repetition rate of ~100 kHz will be used to measure the single-shot spectra at the absorption edges of carbon, nitrogen, oxygen and neon elements. This compact photon spectrometer has a designed resolving power of ~1000 which we have demonstrated at the oxygen K-edge.
Additional Detectors Being Commissioned During Run 22
- DREAM (IP2) Coincident Electron/Ion Spectrometer
Not Available in Run 22
- Double-sided VMI in LAMP (dVMI)
- Co-axial VMI (cVMI)
- Kaesdorf Electron Spectrometer
- Photon Imaging Detectors
For non-standard configuration or more information contact James Cryan (email@example.com).