Introduction

This year’s contribution presents a rich bouquet of distinct applications and developments reflecting the scientific and technical breadth of the beamlines. The chapter is organised into four parts: surface science and magnetism at high pressure, both representative of studies under extreme conditions, and then new applications and further experiments.

Investigations under extreme conditions continue to play a major role in our group. Examples given this year are on low dimensional systems and high pressure applications with emphasis on magnetic properties. Among them, three contributions deal with surface science. A pioneering inelastic X-ray scattering experiment in surface-sensitive geometry has been conducted on the charge-density wave system NbSe2, and further activity in this area should be forthcoming. In other areas such as surface applications to magnetic properties and fast and slow dynamics, nuclear resonance techniques already show their maturity. Investigations of magnetic properties under high pressure and at low temperature are a domain of nuclear resonance scattering especially nuclear forward scattering. Results are presented for samarium and europium chalcogenides, which have quite different behaviours. In the case of samarium emphasis was put on strongly-correlated electron systems and in the case of europium it was on model systems for pure Heisenberg magnetism.

Without new applications and developments something would be missing from our report. Three contributions from very different fields take this into account. Hard X-ray photoemission spectroscopy, developed in the framework of the European project VOLPE, allows one to extend the powerful technique of photoemission spectroscopy to the hard X-ray regime in order to achieve bulk sensitivity. The application of a position sensitive detector in conjunction with an inelastic X-ray scattering spectrometer allowed dispersion contributions to the energy resolution to be overcome and demonstrated the potential for a compact instrument with an energy resolution down to 10 meV. The final contribution shows that inelastic X-ray scattering also has the capability to directly measure the density of phonon states thus complementing inelastic neutron and nuclear inelastic scattering.

In the last section we present a cross-section of a variety of applications. They range from glass physics to the understanding of thermoelectric materials – why they are electric conductors and thermal insulators, then geophysical and biological topics, and finally to fundamental questions in physics.

Besides the scientific activities, the year 2005 had a great influence on the instrumentation as well. The beamlines continued to increase the effective available flux on the sample by various means. Undulators with two different magnetic structures can be optimised for different energy regimes. The first segments of this kind have been installed at ID16, ID18, and ID28. In their final configuration, this will increase the flux between a factor of two and five. Furthermore, the focusing capabilities have been improved at the inelastic scattering beamlines allowing both an optimised and variable setup especially for investigations under extreme conditions.

A major impact is expected from the refurbishment program at ID26, which has just begun. After re-opening of the beamline in summer 2006, two dedicated stations will become available: one for absorption and one for emission spectroscopy. Dedicated spectrometers and focusing devices will also be implemented. The most challenging part will aim at fast time resolved studies (pump-and-probe) and is envisaged at a later stage.

Last but not least external review committees have very positively evaluated ID16 and the nuclear resonance stations (ID18 and ID22N). Their recommendations are currently being analysed and possible implementations discussed.

R. Rüffer