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Technische Universität München> Technische Universität MünchenHelmholtz-Zentrum Geesthacht> Helmholtz-Zentrum GeesthachtForschungszentrum Jülich> Forschungszentrum Jülich

MLZ (eng)

85748 Garching


Materials science diffractometer


In response to the development of new materials and the application of materials and components in new technologies the direct measurement, calculation and evaluation of textures and residual stresses has gained worldwide significance in recent years.

STRESS-SPEC, the materials science diffracto­meter is located at the thermal beam port SR-3 of the FRM II and can easily be configured either for texture analysis or strain measurements.

The set-up utilises three different monochromators: Ge (511), bent silicon Si (400) and pyrolitic graphite PG(002). This selection of monochromators and the possibility to vary automatically the take-off angles from 2θM = 35º to 110º allows to find a good compromise between resolution and intensity for each measuring problem.

The gauge volume defining optical system of primary and secondary slits is designed with regard to reproducibility of geometrical alignment and sturdiness. Both slit systems are linked to the sample table and the detector in such a way that the center of the beam remains the same under all conditions. Instead of the secondary slit a radial collimator can be used in front of the detector. Samples can be aligned using theodolites and a camera system. In addition the possibility to scan surfaces of components offline using a CMM laser scanner is available at STRESS-SPEC.

Typical Applications

Residual stress analysis [1]

  • Industrial components
  • Welds
  • Superalloys
  • Strain mapping
  • Surface measurements from 150 µm possible [2]

Texture determination [3]

  • Global textures
  • Local textures
  • Strain pole figures
  • FHWM pole figures

Structural applications

  • Phase transformation dynamics
  • Spatially resolved phase analysis (e.g. batteries)

[1] Hofmann, M. et al., Physica B, 385‑386, 1035‑1037 (2006).
[2] Saroun, J. et al., J. Appl. Cryst., 46, 628‑638 (2013).
[3] Brokmeier, H.-G. et al., Nucl. Instr. Meth. A, 642, 1, 87‑92 (2011).

Sample Environment
  • XYZ-table
    • capacity 300 kg, Travel xy = ±120 mm, z = 300 mm, accuracy ~ 10 µm
  • Load frame
    • +/- 50 kN, heatable to 1000°C
  • Full circle Eulerian cradle (max. load 5 kg)
  • ¼ circle Eulerian cradle for heavy samples
  • Standard sample environment (e.g. furnace, cryostat)

A positioning system consisting of a Stäubli-6-axes robotic arm for texture and strain measurements (payload up to 30 kg) can be mounted instead of the standard sample table. It offers more flexibility than an Eulerian cradle and can be also used as automatic sample changer for texture measurements [4].

[4] Randau, C. et al., Nucl. Instr. Meth. A, 794, 67–75 (2015).

Technical Data

Neutron beam

  • SR-3 thermal neutrons
  • Collimators (‘in-pile’) 15’, 25’, open


  • Ge(511), Si(400), PG(002)
  • M 35° – 110° continuous
  • Wavelength 1 Å – 2.4 Å ; (2.5 Å-1 < Q < 10.5 Å-1)

Possible slit size – Residual Stress

  • Primary slit: automatic continously variable up to 7 × 17 mm2 (W x H)
  • Secondary slit: continuously variable up to 15 mm
  • Radial collimators (FWHM = 1 mm, 2 mm, 5 mm, 10 mm)

Possible slit size – Textures

  • Primary slit: max. 30 x 40 mm2 (W x H)
  • Secondary slit: continuously variable up to 15 mm or open


  • 3He-PSD, 25 × 25 cm2; 256 × 256 pixel

Instrument Scientists

Dr. Michael Hofmann
Phone: +49 (0)89 289-14744

Dr. Weimin Gan
Phone: +49 (0)89 289-10766

Dr. Joana Rebelo-Kornmeier
Phone: +49 (0)89 289-14710

Phone: +49 (0)89 289-14814

Operated by

TU Clausthal


Find the latest publications regarding STRESS-SPEC in our publication database iMPULSE:

Citation of the instrument

Heinz Maier-Leibnitz Zentrum. (2015). STRESS-SPEC: Materials science diffractometer. Journal of large-scale research facilities, 1, A6.

For citation please always include the DOI.


© W. Schürmann, TUM

Slit-system for residual stress analysis

Robot at STRESS-SPEC holding a copper tube for combined texture and strain measurements.

Resolution function
Resolution function

Resolution function for different monochromator options

MLZ is a cooperation between:

Technische Universität München> Technische Universität MünchenHelmholtz-Zentrum Geesthacht> Helmholtz-Zentrum GeesthachtForschungszentrum Jülich> Forschungszentrum Jülich