Scientists in charge




Beamline and
Kappa diffractometer

Nathalie Boudet
Institut Néel
Nils Blanc
Institut Néel

d2am : (+33)4 76 88 25 94

d2am : (+33)4 76 88 21 88
Small Angle Scattering
soft condensed matter
+(33)4 76 51 47 85
hard condensed matter
Fréderic De Geuser
(+33)4 76 82 66 12


Description of the D2AM optics

The optic has quite a symmetrical design and consists of a two crystal monochromator with sagittal focusing (mainly Si(111) but Si(311) is available) located between two cylindrically bent mirrors in a compact arrangement, with double focusing (3:1).

  1. Point focusing of the beam on the crystal at fixed sample position; less than 0.3x0.3 mm2 can be reached at sample position
  2. High energy resolution: 2-5 eV; DE/E~ 2.10-4
  3. High Q resolution; DQ/Q~ 10-3 - 10-4
  4. Accessible wavelength range: 0.5-2.5 Å, i.e. about 25-5 keV;
  5. High rate of harmonic rejection: higher than 10-4.
  6. With focusing typical angular divergences are 3.10-4*3.10-3rd^2 (vertical*horizontal) for a beam size of 3*30mm2 on the monochromator.

The main distances between optical elements are :

  • source - primary mirror : 26.055 m
  • source - monochromator (1st crystal) : 28.027 m
  • source - second mirror : 29.763 m
  • monochromator - goniometer centre : 9.771 m
  • The beamline slits are located at 24.470m, 31.470m, 35.295m from the source.
  • source - SAXS slits : 40.745 m

For an exhaustive beamline description, refer to JL Ferrer et al., J Synchrotron Rad. (1998) p1346-1356.


Small angle camera:

A modular Small Angle Scattering camera with different sample changers and camera lengths, with three options:

  • very small angle (q > 6.10-4 Å-1 at 8keV) with high position stability; mandatory collaboration with the local contact.
  • regular SAXS for soft condensed matter, with possibility to insert sample holders for time-resolved experiments (3.5 10-3 Å-1<  q  < 0.3 Å-1)
  • Anomalous SAXS (recommended collaboration) (10-2 Å-1< q < 1Å-1)

For complementary informations, refer to JP Simon et al., J. Appl. Cryst. (1997). 30, 900-904.

"Kappa" diffractometer:

The KAPPA diffractometer for Materials Science is driven with the spec-kappa geometry. It leaves a large free space to adapt sample environment. For the detection, vertical rotation axis NU and horizontal axis DELTA (-5°, + 130°) can carry an optional vertical analyser. All the angular motions have a resolution lower than 0.001°, the confusion sphere being smaller than 0.05 mm. Using a Si (311) analyser, FWHM less than 0.02° (2THETA) should be reached with powder samples. An optional goniometer-head (two translation on top of two cradles) is available on top of the kappa head for surfaces applications.

Various sample environments are available.