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Methoden und Instrumentierung Poster: Mi., 14:00–16:30 M-P79
AMOR a versatile time-of-flight polarized neutron reflectometer at SINQ/PSI
Jochen Stahn 1 , Mark Koennecke 1 , Thomas Gutberlet 1
1 Lab. f. Neutron Scattering, ETHZ PSI, 5232 Villigen PSI, Switzerland
AMOR the apparatus for multi-option reflectometry at SINQ/PSI is a multi purpose
state of the art reflectometer adaptable to the experimental demands of surface
and interface studies in various fields of research. Phenomena to be challenged may relate
to growth, wetting, absorption, adhesion, (inter-)diffusion, corrosion, nanocrystals,
surface magnetism, magnetic excitation, thin film super-conductivity, polymer films,
biomembranes, Langmuir films and more [1,2].
Measurements with polarized or unpolarized neutrons in white beam time-of-flight
mode (1.3 ˚A < λ < 13 ˚A) and optionally in monochromatic θ-2θ mode can be performed.
Most of the components are riding on an 8 m optical bench so that the chopper -
detector distance can be varied in order to give an optimal sample illumination and
resolution (∆q/q = 0.5-10 %). The scattering plane is oriented vertically to allow also
measurements at liquid surfaces. The inclination angle and thereby the accessible qrange
is adjusted by tilting a deflection mirror and/or the sample. A flexible software
control of the θ-2θ-movement around axis that are not mechanically coupled has been
implemented.
The standard mode of the instrument is time-of-flight, which has been opened for user
operation in Oct. 2002. Two single detector tubes can be operated alternatively with
an area detector. The area detector system allows coverage of off-specular reflectivity
to map reasonable space in qz and qx. Polarized neutrons are provided via a polarizing
supermirror of FeVCo/Ni to perform full spin polarized and analyzed reflectometry
measurements. The flexibility of the instrument also allows for large sample environments,
such as cryomagnets, evaporation chambers, furnaces or Langmuir troughs.
Experiments at AMOR have included measurements of polymers at air-water interfaces,
adsorption of model membrane systems to polymer cushions, structural fluctuations
and dynamics in block co-polymers, magnetic multilayer systems of FM/AM/FM
multilayers or HTSC/AM layer systems, diffusion in intermetallic layers. Results and
performance of AMOR will be presented and discussed.
[1] D. Clemens et al., Physica B 276-278 (2000) 140.
[2] M. Gupta et al., Pramana J. Phys. 63 (2004) 57.