PRESENT STATUS OF THE TOPOGRAPHY AND HIGH-RESOLUTION DIFFRACTION BEAMLINE AT THE ESRF

We present a preliminary design of the topography and high-resolution diffraction beamline (BL16, ID19) at the ESRF. Its main characteristic s derive from the requirements of having a almost-equal-to 40 (horizon tal) x 14 (vertical) mm2 spectrally and spatially homogeneous beam, a high photon flux and a tunable photon energy at the sample position. T his implies the choice of a high-field, 11-pole wiggler with a variabl e gap as source, a 140 m long beamline, and different types of filters . The experimental station is located in a satellite laboratory. The m onochromators will either produce a wide- or a narrow-bandpass beam. T he experimental hutch is designed to use either white or monochromatic beams, and to host either instrumentation with a heavy sample environ ment or with a high-precision setting for high-resolution diffraction and topography. Finally we point out the facilities which will be avai lable for beamline users.