D1B is a two-axis spectrometer dedicated to diffraction experiments requesting a high neutron flux. A great number of experiments performed on D1B concern the determination of magnetic structures. At small angles where the magnetic peaks are expected, a high spatial resolution can be achieved, the FWHM reaches 0.2° (for a sample with  = 8 mm).

Three pyrolitic graphite monochromators focusing onto the sample position provide a flux of 6.5·10⁶ n cm^-2s^-1. A second wavelength with = 1.28 Å is available by using a germanium monochromator.

D1B is equipped with ³He/CF₄ position-sensitive detector composed of a system of multi-electrodes with 1280 cells of 100 mm of height with a separation of 0.1º, covering in total 128º ranged from 0.8 to 128.8º in 2θ.

A radial oscillating collimator (ROC) can be placed between the sample and the position sensitive detector. It will reduce considerably the signal scattered by the non Vanadium based sample environment (e.g. cryofurnaces, cryomagnets, niobium  furnaces, etc...), allowing the utilization of a wide range of setups in the new D1B diffractometer.

The specially designed cryostat is known for its low background crucial for some experiments with small intensity changes.

Because of its high flux at = 2.52 Å together with the large multi-detector, surface studies such as adsorbed phases as well as real-time diffraction experiments are possible. Collecting a diffraction pattern with sufficient statistics in minutes (1-5 min) even seconds allows in situ studies of reaction kinetics. A fast detection of phase transitions can also be obtained by scanning the temperature. A complete thermal variation of the diffraction patterns (1.5 - 300 K) can be achieved in few hours (3-5h).

The texture of polycrystalline samples can also be investigated using the Eulerian cradle available on D1B. Scanning in and at 2 or 3 positions allows the complete determination of the pole figures in typically one day for one sample.

D1B is now controlled by a Linux workstation on which data reduction and treatment programs are also available. The raw data are on-line corrected for efficiencies of the detector cells. In addition a Silicon graphics workstation with a direct internet connection is also installed in the cabin of D1B. More sophisticated programs with graphical user interface for data visualisation (2-dim and 3-dim. plot displays, LAMP Large Array Manipulation Program ) and analysis (Rietveld and integrated intensities) are running on the SGI workstation. A PC computer running under Microsoft Windows is also available for data treatment and analysis in the cabin of D1B.