Scope of the workshop
The actual status is that reflectometers play its important role in the park of spectrometers at all neutron centres. The still present question about advantages of TOF or constant wavelength reflectometers will be the starting point on this workshop.

In the combination with polarised neutrons with polarisation analysis different solutions exist and the most efficient method has to be worked out. Off-specular scattering shows since some time its importance because it gives in a non-destructive way access to the inner structure of multilayers ranging from nano-structured magnetic devices to biological multilayers. The experimental requirements are often not fully adapted, because in this area is still a certain lack of theoretical treatment of the data. In particular the appearance and implication of spin-flip scattering in various parts of the 2-dimensional scattering map needs discussion and reflection on the instrumentation. The extension to reflection in transmission or pure transmission are necessary thoughts. Right now new methods are turning up which should lead to the realisation of 3-dimensional polarimetry in reflectometry. Thus it will be possible to study complex layer-magnetisation structures including out-of-plane magnetisation. Larmor precession will play an important role in this task and will impose new set-up’s in instrumentation. Off-specular scattering consists in fact of GISANS measurements being integrated over one co-ordinate. Thus it is evident that the full analysis of GISANS spectra gives more information about the shape, size, location and magnetisation of the objects creating off-specular scattering. It should be pointed out that a "single" GISANS spectrum will not give the full information. It should be worked out with how many single shots an optimal degree of information will be obtained. GISANS requires different experimental restrictions in collimation and in particular for polarisation analysis, for which solutions should be elaborated. A special topic will be incoherent scattering in reflectometry and whether this task can be solved with polarised neutrons and what instrumentation would be needed in particular for biological samples. In general the lay-out of reflectometers will be discussed including polarised neutrons and polarisation analysis. Further development with Larmor precession and spin-echo is included. The question of GISANS on existing SANS spectrometers is raised and what development is needed for magnetic GISANS using again Larmor precession. Finally the equipment with polarised neutrons for a reflectometer dedicated for biology (horizontal geometry) will be discussed including the possibility of 3He-filter and super-mirror analyser.

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Preliminary Programme:
Topics:
• Reflectometers in TOF and/or monochromatic mode
• Off-specular scattering distribution for + and – Qx and beyond the horizons
• Yoneda-scattering, super-Yoneda scattering and Bragg-sheet scattering
• Magnetic scattering: spin-flip scattering in specular reflection and off-specular scattering
• How to approach 3-dimensional polarimetry
• The role of Larmor precession in the scattering process and in instrumentation
• Complementarity of off-specular and GISANS
• Magnetic scattering in off-specular scattering and in GISANS
• Possibility of using 3He-filter and supermirror
• Polarised neutrons for incoherent scattering in reflectometry
• A look to magnetic scattering and GISAXS at ESRF

support
Nmi3 support this school. Contribution to travel and living expenses of participants. (Preferent students and Post-Docs). the grant recipients have to hold a European nationality distinct form the one of the ocuntry hosting the workshop.

Organizer
Dr. Hans Lauter
Phone:476207239
Email: lauter@ill.fr

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