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Materials Chemistry- EH3

The materials chemistry hutch at ID15A is devoted to operando and time resolved diffraction and imaging, total scattering, and diffraction computed tomography. The station is optimised for rapid alternation between the different techniques during a single operando experiment in order to collect complementary data on working systems. The high available energy (up to 120 keV) means that even bulky and highly absorbing systems may be studied. The combination of the beamline's optimised focusing optics and a photon counting CdTe pixel detector allows for both unprecedented data quality at high energy, and for very rapid triggered experiments.

Key points

  • Energy range, monochromatic 40 < E < 120 KeV
  • Beam sizes from 0.3 µm to 8 mm

Techniques

  • Angular dispersive diffraction using area detectors
  • Pair distribution function experiments
  • X-ray imaging, fast tomography, diffraction tomography

Experimental hutch overview

As shown below, EH3 contains four main elements mounted on highly stable granite platforms. From right to left, these are 1) Secondary focusing using compound refractive lenses; 2) A sample stage containing both heavy and light duty sample towers; 3) A detector stage with long translations; and 4) An ancillary table offering the ability to mount a SAXS detector.

The following experimental configurations are available in standard operation:

 

XRD-/PDF-/SAXS-CT

Abs-/Phase-Contrast-CT

High Precision Total Scattering

High Frequency Time-Resolved

Energy (keV)

20 – 140

20 – 140

60 – 140

20 – 140

Primary Optics

LLM/DMLM

LLM/DMLM/Pink

LLM/DMLM

LLM/DMLM

Secondary Optics

TF/CRL/KB

-

TF

TF/CRL/KB

Beam size

 

 

 

 

   Vertical (µm)

0.3 – 20

< 6

100 – 200

15 – 200

   Horizontal (µm)

0.3 – 50

< 8

100 – 200

20 – 200

Spatial Resolution

 

 

 

 

   Vertical (µm)

> 0.3 µm

0.6/1.4/3.1

-

 

   Horizontal (µm)

> 0.3 µm

0.6/1.4/3.1

-

 

Detector

Pilatus/Maxipix

Imaging Detectors

Pilatus

Pilatus/Maxipix

Goniometer

HR

HR

HR/HL

HR/HL

X-ray diffraction detectors

EH3 is equipped with a Dectris Pilatus3 X 2M utilising a CdTe sensor. This detector gives unprecedented data quality at high energy, as can be seen in the comparison of its characteristics with respect to a conventional flat panel detector such as the commonly used Perkin Elmer XRD 1621, and in the comparison between data taken in identical conditions with the two detectors.

 

Pilatus3 X CdTe 2M

Perkin Elmer XRD 1621

Detection technology

Hybrid photon counting

Flat panel

Sensor material

CdTe

CsI

Pixel size [µm2]

172172

200200

Total number of pixels (H V)

14751679

20242024

Maximum frame rate (Hz)

250 (500 with ROI)

15 (30 with 22 binning)

Point Spread Function (FWHM)

1 pixel

2 pixels

Energy threshold (keV)

8 – 40

none

Maximum count rate (ph/s/pixel)

5106

Integrating detector

Non linearity

< 2% at 106 counts/s/pixel

 

Counter depth

20 bit

16 bit

Dynamic range

20 bit

12.8 bit

Minimum exposure (ns)

200

3.3107

Image lag

0

~1% after 100ms

Readout time

0.95 ms

 

File format

CBF, HDF5

Multiframe EDF

X-ray imaging detectors

A range of imaging cameras are available for experiments which require complimentary absorption tomography. These detectors are permanently mounted and can be used sequentially with the diffraction and/or SAXS detector and one another. The detectors system characteristics are listed below.

 

 Low resolution

              High resolution

Objective magnification

10×

20×

pixel size [μm2]

6.56.5

3.253.25

1.31.3

0.650.65

0.330.33

Field of view [mm2]

16.614.0

8.37.0

3.32.8

1.71.4

0.830.70

Number of pixels

25602160 (HV)

Readout noise (rms)

1.5 e-

Dark current

0.6 e-/pixel/s

Minimum exposure time [ms]

0.5

Maximum frame rate

100Hz @ 25602180 pixels ROI

838Hz @ 2560256 pixels ROI

File format

HDF5, multiframe EDF

SAXS detector

ID15A is equipped with a single photon counting Maxipix CdTe detector (Ponchut, et al., 2011) for time-resolved high energy SAXS. Measurements over a q-range from 0.01 to 1 nm-1 are possible at 30 keV, and the CdTe sensor ensures that much higher incident energies can also be used.  The maximum frame rate is 350 Hz, making it particularly well suited for time-resolved experiments and SAXS-CT. In addition to the standard acquisition mode, the detector features, similar to the Pilatus3 detector, there is an electronic gating option with a minimum exposure time of 100 ns. This opens new possibilities for high energy time-resolved SAXS experiments on the sub-microsecond time scale using a stroboscopic approach as already demonstrated with the Pilatus detector. The main detector parameters are listed below.

Detection technology

Hybrid photon counting

Sensor material

CdTe

Pixel size [µm2]

5555

Total number of pixels (HV)

512512

Maximum frame rate

350 Hz

Point Spread Function (FWHM)

1 pixel

Energy threshold

6 – 100 keV

Maximum count rate

2105 ph/s/pixel

Counter depth

11810 counts

Dynamic range

1:11810

Minimum exposure

100 ns

Image lag

0

File format

HDF5, CBF, EDF

Ancillary probes

The beamline retains access to all of the equipment held in the sample environment pool. In addition, several dedicated probes are available for simulataneous measure during scattering and/or imaging experiments. A dedicated Bruker Vertex 80 spectrometer, a Hiden QGA mass spectrometer are available for operando experiments. Together with our large stock of mass flow controllers, regulators and fittings, this means that custom experiments for e.g. heterogeneous catalysis may be performed. The IR detector and sample chamber are shownn below mounted on the beamline.

A Hitachi Vortex®-EM silicon drift X-ray fluorescence detector with a special 1mm thick Si crystal for high energies is available. The detector is combined with a fast Mercury/XIA readout electronics allowing exposure times of a few milliseconds. The Vortex detector can be used to perform simultaneous fluorescence mapping and XRD mapping or fluorescence CT and XRD-CT.

Sample environments

A number of sample environments are available to control the sample temperature between about 80 - 1500 K. Lower temperatures are avaliable with equipement from the sample environment pool.

Device

Temperature range (K)

Temperature Resolution (K)

Sample size

Oxford 800plus Cryostream

80 – 500

1

< 2 mm

Linkam THMS-600 Furnace

80 – 800

0.2

Capillary, film

Tomography Furnace

300 – 1500

10

< 10 mm

ESRF Gas Blower

300 – 1273

10

< 3 mm

Scientific Techniques

The new beam line makes techniques like diffraction tomography, pair distribution function analysis, and ultra-fast hight energy diffraction routinely accessible to the full ESRF user community. Please see the Scientific Examples page for more information.