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An Office of Science User Facility

Atomic, Molecular & Optical Science (AMO)

This site is OBSOLETE as of 30 Oct. 2017
Please go to the new AMO site
 

 

AMO Standard Configuration for Run 16

Types of Experiments

With this new standard configuration, AMO will be able to support various time-resolved X-ray and/or IR pump X-ray probe experiments examining the ultrafast molecular dynamics in gas phase.

X-ray and X-ray Focus

X-ray energies ranging from 280 to 2000 eV will be available. Soft X-ray self-seeding, two-color FEL, and two-pulse operations will be offered as part of the standard configuration.

AMO’s KB focusing system can provide focus down to 2 micron (FWHM) and is adjustable in size up to several 100s of microns FWHM.

Optical Pump Lasers

Time-resolved experiments employing tunable femtosecond pulses will be supported under this standard configuration. The fundamental and harmonics (800, 400 and 267 nm) from the AMO, ~50 fs Ti:Sapphire laser will be available, delivered to the target collinearly with the x-rays, with in-coupling ~35 cm upstream of the interaction, and with the focusing lens ~1000-1500 mm away from the same. The achievable maximum peak intensity/fluence will be determined by the existing optical system and will not be modified. Contact the AMO scientists to discuss specific needs and to confirm whether they can be achieved in this standard configuration of the laser.

Timing diagnostics

The AMO transmission sample system time-tool will be available to record single shot arrival times (t<100 fs) that can be post-sorted. A jitter-corrected plot can be shown online during the experiment provided the x-ray is not too attenuated. Coarse temporal overlap (t<20 ps) can be obtained via photoelectric effect monitoring on an SMA wire at the interaction (on the focus paddle). Finer time zero determination at the focus is typically optimized using ion time of flight.

Sample delivery

The standard gas delivery setup will be a single or double skimmer stage with differential pumping. A pulsed Even-Lavie valve will be offered as part of the standard configuration. For detailed information, please contact AMO scientists.

Detectors

A high-resolution double-sided velocity map imaging (VMI) spectrometer, designed for the LAMP chamber will be supported. This spectrometer has a longer side, which is typically biased to measure ions, and a shorter side for electrons. The spectrometer is capable of measuring a full 4pi solid angle of fragments. With the typically used voltages the ion side detects kinetic energies up to 50 eV with time-of-flight resolution of 100ps. The electron side has energy resolution of up to 75, and collects 4pi of up to 150 eV energy electrons. If only one side of the spectrometer needs to be operational at a time, higher energy particles can be captured. As an alternative, flat field arrangement can also be achieved.

The detector in the ion-side is a Roentdek delay-line detector, DLD120. A Z stack MCP measures time of flight while the 120mm square delay-line anode enables the position detection. The electron side detector consists of an MCP-phosphor screen assembly. The phosphor screen is of highest imaging quality P47 grade, which emits blue light with ~100 ns decay constant, that allows for fast hit processing.

 

AMO Instrument Staff

Timur Osipov, Dipanwita Ray, Stefan Moeller, Giacomo Coslovich, and Michael P. Minitti

Parameter Table

To be considered for scheduling in this standard configuration, users will be required to include a table in the proposal that lists the specific experimental parameters to ensure compatibility with these configurations. If the experimental parameters are not compatible with the standard configuration or if the table of parameters is incomplete, the proposal will be reviewed and considered for scheduling as general user proposal. Please see the  table of required parameters. No fundamental changes to the standard configurations will occur, but some details of the configuration may be updated in response to inquiries, so users should recheck the website before submitting your proposal to confirm that you have the latest information. Address any questions to the instrument staff.
 
 
LCLS proposals are submitted through the User Portal.

SLAC SLAC National Accelerator Laboratory, Menlo Park, CA
Operated by Stanford University for the U.S. Dept. of Energy