Present status of the topography and high-resolution diffraction beamline at the ESRF

The authors present a preliminary design of the topography and high-resolution diffraction beamline (BL16, ID19) at the ESRF. Its main characteristics derive from the requirements of having a approximately=40 (horizontal)*14 (vertical) mm 2 spectrally and spatially homogeneous beam, a high photon flux and a tunable photon energy at the sample position. This implies the choice of a high-field, 11-pole wiggler with a variable gap as source, a 140 m long beamline, and different types of filters. The experimental station is located in a satellite laboratory. The monochromators may either produce a wide- or a narrow-bandpass beam. The experimental hutch is designed to use either white or monochromatic beams, and to host either instrumentation with a heavy sample environment or with a high-precision setting for high-resolution diffraction and topography. Finally they point out the facilities available for beamline users.