Powder Diffraction: CuKa Rotating Anode Radiation Source

The Powder Diffraction Laboratory is a support laboratory for MCX, XRD and XAFS beamlines, providing diffraction measurements, in Bragg-Brentano geometry, of powders, thin films, and single crystals.
The aim of the laboratory is to provide an offline facility both for diffraction measurements and support activities like the evaluation of the quality of the sample (i.e. degree of crystallinity) and/or the its characterization (i.e. identification of the phases, crystal simmetry, etc.)  


For any questions and access requests, please contact: Luca Rebuffi


The Source

The laboratory is equipped with a 5 KW Nonius-Bruker FR591 Cu Rotating Anode source (Emission Energies: Kα1 = 8.048 KeV, Kα2 = 8.028 KeV).

The beam is focalized and monochromatized with a Osmic Confocal MaxFlux™ (multilayer) optic system.

This optic part is a two-dimensional reflection system, realized by using two mirrors in a "side- by-side" Kirkpatrick-Baez scheme. Each mirror independently reflects x-rays in one of the two perpendicular direction, and are positioned at a position appropriate to optimize performance parameters including flux, spectrum and divergence.

The spot size, at the exit of the monochromator position, is a 1 × 1 mm square, giving a 6.5·108 photons/sec of maximum flux at the quote of the sample.

The beam is collimated by a Huber 135 mm collimator (0.8, 0.5, 0.3 mm available), reducing both the spot size and the divergence.

The Diffractometer

The station is equipped with a 8 axis Huber diffractometer, designed for powder diffraction measurement. Its system of axis can provide the typical ω-2θ scan, with the possibility of tilting the sample (ψ angle) for stress and strain measurments, and providing the φ angle rotation for texture measurements.

Powder diffraction samples are prepared in flat plate configuration, on circular sample holders (designed to be used also in the MCX beamline with a central cavity for the powders (dimensions: 10 mm diameter × 1 mm height). Sample holders can be mounted in a steady support or in a spinning support.
A special support for heavy weight samples (up to 4 kg) is available in order to hold, for example, manufactured metallic parts.
Ad-hoc supports and/or sample holders can be prepared by the Support Lab .

The 2θ axis is equipped with a 250mm vacuum pipe (10-2 mbar) in order to suppress noise and reduce the air absorption of the diffracted signal.



The diffractometer is mounted on a motorized basement with a translational (orthogonal to the beam) and a rotational (with the same center of rotation of ω and 2θ axis) movements for the precise (fine) alignement of the diffractometer with the beam.

The instrumental profile (Caglioti's equations) is periodically calculated with a LaB6 NIST 660a powder sample.

XRF instrumentation is also available (Amptek XR-100T photodiode + Amptek MCA800D) for chemical speciation of the samples (up to Z = 28).


 

Specifications

Diffractometer Type Huber 8-axis Diffractomter
Angular ranges 2θ = 0° ÷ 140°
ψ = -52° ÷ +52°
φ = 0° ÷ 360°
Source 5KW Nonius-Bruker FR591
Rotating Anode source
Spot circular - 200÷500 μm in diameter
Flux 6.5·10photons/sec at 5KW
Energy Copper Kα1 = 8.048 KeV
                      +
Copper Kα2 = 8.028 KeV

 


Accessories

Sample Holders Powder diffraction:
Flat Plate configuration
with a circular cavity of 
10 mm diameter x 1 mm height

Thin Films and Single Crystals:
ad-hoc sample holders
Sample Holder Supports Steady Support
Spinning Support
Heavy Weight Support
Collimators Huber 135mm collimators:
0.8, 0.5, 0.3 mm
XRF Amptek XR-100T Si-Pin Photodiode (145 eV @5.9 KeV)

+

Amptek MCA8000D Pocket MCA
Last Updated on Wednesday, 22 July 2015 18:03