Run 20 Capabilities

NEH 2.2 Capabilities for Run 20

chemRIXS Capabilities #1

chemRIXS Capabilities 1 for Run 20

The chemRIXS instrument is a new endstation targeting spectroscopic studies of samples in solution using monochromatic soft x-ray pulses and a tunable optical laser pump.  The endstation is equipped with the following:

  • Liquid jet delivery via a microfluidic chip
  • A load-lock chamber that allows for rapid chip exchange
  • Catcher for capturing and/or re-circulating sample
  • Viewing and illumination
  • Diagnostic paddle for calibration targets, spatio-temporal overlap, etc.
  • Laser in- and out- coupling
  • Detectors optimized for x-ray absorption and emission spectroscopies
  • Arrival time monitor located ~1.5 m from the interaction point

Performance Parameters for Run 20:

X-ray Parameters 

 

Laser Parameters

Repetition rate (Hz)

Up to 120

 

Repetition rate (Hz)

120 

Energy Range (eV)

250 - 1100

 

Wavelength (nm) 

400, 800, 480 - 900 (tunable)

Spot Size (um), H x V

10 x 10, min

1000 max

 

Pulse Duration (fs)

<40 @ 800 nm

Energy per pulse (uJ)

>2

 

Fluence (mJ/cm2)

>50

Pulse Duration (fs)

<40

 

Spot size (um)

Min <50 X 50, option for 1:4 aspect ratio with <50 minor axis

Beamline Resolving Power 

>2,000

 

Polarization control

Horizontal and vertical, circular at select wavelengths

Temporal resolution (fs)

<60

 

Arrival time monitor precision (fs)

<20

Polarization

Linear horiz.

     

Wavelength scanning

Yes

     


The following detectors will be provided to the users:

  • Avalanche PhotoDiodes (APD) and Large area photodiodes.  The APDs are single-photon sensitive fast detectors suitable for X-ray Absorption Spectroscopy (XAS) in Total Fluorescence Yield (TFY) mode.  These detectors will be mounted on an in-vacuum rotatable stage and can be placed in the horizontal scattering plane.
  • Andor Newton_SO, 512 X 2048 pixels, 13.5 microns pixel size, capable of full frame read-out at 120Hz when operated in Full Vertical Binning mode.  This CCD detector will be placed outside chemRIXS in the path of the direct beam and will allow for measuring XAS in transmission when using thin sheet jets
  • Portable Varied-Line Spacing (VLS) X-ray Emission Spectrometer (XES).  This is an existing XES spectrometer with resolving power of ~2000, that will nominally be equipped with the abovementioned Andor Newton_SO CCD.  The spectrometer will be mounted in the horizontal plane at 45 degrees with respect to the X-ray beam.

The community is encouraged to propose experiments focusing on the following techniques:

  • Time-resolved XAS, which can be implemented in three modes:
    • Direct transmission (for samples delivered in the form of a thin sheet jet)
    • TFY mode, using the in-vacuum APD
    • Partial Fluorescence Yield (PFY) mode, using the VLS spectrometer
  • Time-resolved XES, using the VLS spectrometer with non-resonant excitation

Users are encouraged to contact Georgi Dakovski, dakovski@slac.stanford.edu  and Kristjan Kunnus, kristjan@slac.stanford.edu for more information.

chemRIXS Capabilities #2

 

chemRIXS Capabilities 2 for Run 20

For a limited time chemRIXS will offer a second standard configuration.  The major difference will be the relocation of the Portable VLS spectrometer from the port at 45 deg with respect to the incoming beam on chemRIXS to the direct beam several meters downstream of the endstation.  This configuration is offered specifically for experiments that meet the following conditions:

  • Can only work with thin sheet jets in transmission mode
  • Wish to carry out X-ray Absorption Spectroscopy by energy dispersing the beam after interaction with the sample
  • Wish to carry out experiments in non-monochromatic mode at the beamline, e.g. to take advantage of:
    • High peak power offered when the beamline is operated in zero-order mode
    • Special modes of operation of the accelerator, e.g. 2-color experiments
    • Extremely short FEL pulses
    • Wide bandwidth pulses for covering a wide spectral range       

A dedicated entrance slit will be installed on the beamline that will define the source point of the spectrometer.  Only experiments that clearly state the need to use this configuration, by addressing all of the conditions listed above, will be deemed technically feasible.

 

The following detectors will also be provided to the users:

  • Avalanche PhotoDiodes (APD) and Large area photodiodes.  The APDs are single-photon sensitive fast detectors suitable for X-ray Absorption Spectroscopy (XAS) in Total Fluorescence Yield (TFY) mode.  These detectors will be mounted on an in-vacuum rotatable stage and can be placed in the horizontal scattering plane.

The sample delivery, optical laser parameters and nominal x-ray parameters are identical to Standard Configuration 1.  For the availability and details about special modes of FEL operation, e.g. 2-color operation, please consult with beamline scientists.

Users are encouraged to contact Georgi Dakovski, dakovski@slac.stanford.edu  and Kristjan Kunnus, kristjan@slac.stanford.edu for more information.

qRIXS

qRIXS Sample Chamber for Run 20

The qRIXS Sample Chamber is part of the qRIXS instrument which consists of the Chamber and a Spectrometer arm suitable for x-ray emission spectroscopy.  For Run 20 ONLY the Sample Chamber will be available to users, contingent on timely assembly, installation and commissioning.  The Chamber is suitable for experiments focusing on X-ray Diffraction/Resonant Elastic X-ray Scattering, X-ray reflectivity, and X-ray Absorption Spectroscopy.  The following capabilities will be provided:

  • Sample positioning on an in-vacuum diffractometer, 6 degrees of freedom, sphere of confusion <50 microns
  • At the moment only bulk samples and thin films on substrates will be considered
  • A load-lock chamber  
  • Sample cooling, ~ 25 K
  • Diagnostic paddle for calibration targets, spatio-temporal overlap, etc.
  • Laser in- and out- coupling
  • Detectors optimized for x-ray absorption and diffraction
  • Arrival time monitor located ~1.5 m from the interaction point

Performance Parameters for Run 20:

X-ray Parameters 

 

Laser Parameters

Repetition rate (Hz)

Up to 120

 

Repetition rate (Hz)

120 

Energy Range (eV)

250 - 1100

 

Wavelength (nm) 

400, 800

Spot Size (um), H x V

10 x 10, min

1000 max

 

Pulse Duration (fs)

<40 @ 800 nm

Energy per pulse (uJ)

>2

 

Fluence (mJ/cm2)

>50

Pulse Duration (fs)

<40

 

Spot size (um)

Min <50 X 50, option for 1:4 aspect ratio with <50 minor axis

Beamline Resolving Power 

>2,000

 

Polarization control

Horizontal and vertical, circular

Temporal resolution (fs)

<60

 

Arrival time monitor precision (fs)

<20

Polarization

Linear horiz.

     

Wavelength scanning

Yes

     

The following detectors will be provided to the users:

  • Avalanche PhotoDiodes (APD) and Large area photodiodes.  The APDs are single-photon sensitive fast detectors suitable for X-ray Absorption Spectroscopy (XAS) in Total Fluorescence Yield (TFY) mode, and for X-ray Diffraction.  These detectors will be mounted on an in-vacuum rotatable stage (2-theta arm) and can be placed in the horizontal scattering plane.

Users are encouraged to contact Georgi Dakovski, dakovski@slac.stanford.edu for more information.