Introduction

A large variety of experiments covering a wide range of scientific topics and applications were conducted on the beamlines of the High Resolution and Resonance Scattering Group in 2003. Since it is impossible to report on all of them, two main areas have been selected: "Studies under extreme conditions" and "Studies of glasses and disordered systems". Both topics are excellent examples of the complementarity of the different techniques and the increasing complexity of the sample environment (high-pressure, external magnetic fields and low/high temperatures).

Another important research field deals with nano-structured materials, surfaces, interfaces, and multilayers. First investigations on diffusion of iron within iron films on MgO and in iron islands (coverage about half a monolayer) on vicinal tungsten showed an enhanced diffusion characteristic compared with bulk [1]. Magnetic properties of iron islands on tungsten could be investigated utilising nuclear resonance scattering techniques and a newly-applied theoretical formalism [2]. Further activities comprise the study of the high-frequency dynamics in quantum liquids such as neon [3]. Finally, the determination of the phonon dispersion in tiny single crystals (down to a few 10-5 mm3) remains an active field of investigations. Examples are the studies on HgBa2CuO4 [4]and graphite [5].

Beamline instrumentation and sample environments were also an important area of effort, complementing the scientific research. Along with the optimisation of insertion devices for highest brilliance, cooling of the first optical element (the high heat-load monochromator) is crucial for our beamlines. Studies show that the applied cryogenic cooling scheme is capable of preserving the quality of the most powerful beam delivered by the X-ray source to date. Furthermore, this system should be able to handle the higher heat-loads envisaged in the future [6]. The demand for the investigation of micrometre-sized and "nano-structured" materials makes micro-focusing indispensable. Thanks to the in-house development by the Optics group, Kirkpatrick-Baez (KB) optics and compound refractive lenses (CRL) have been, or will be, installed at all our beamlines

The closing article on "Thermal-motion-induced Scattering from Zinc Oxide" from the CRG beamline BM28 shows nicely that "forbidden" reflections are not only the privilege of nuclear resonance scattering but may also appear due to electronic resonances.

R. Rüffer

References
[1] M. Sladecek et al., Surface Science 507-520, 124 (2002); M. Sladecek et al., Surface Science (2004).
[2] R. Röhlsberger et al., Phys.Rev. B 67, 245412 (2003).
[3] A. Cunsolo et al., Phys.Rev. B 67, 024507 (2003).
[4] M. D'Astuto et al., J. Phys.: Cond. Matt. 15, 8827 (2003).
[5] J. Maultzsch et al.; Phys. Rev. Lett., in print.
[6] A.I. Chumakov et al., article in the Methods and Instrumentation chapter of this Highlights.