Simulated experiment

ADAM operates as a fixed wavelength neutron reflectometer

  • The neutron beam from the cold neutron guide H521 arrives at the monochromator which selects a narrow wavelength band.
  • A beryllium (Be) or a solid state filter suppresses the unwanted harmonics. Optionally the beam can be polarised simultaneously (i.e. select only the neutrons which have spins all in the same direction).
  • The monochromatic beam is shaped by a set of slits and can be shut-off by a beam shutter.
  • A first flipper makes it possible to flip the polarisation direction at will.
  • The monochromatic polarised beam is then reflected by the sample.
  • A second flipper and an analyser measure the change in the beam polarisation introduced by the sample.
  • The measurement is performed by scanning the sample orientation in steps to change the incidence angle. The measurement is either specular (emerging angle = incidence angle) or off-specular (unequal angles). When using the position-sensitive detector both are measured simultaneously.

These measurements make it possible to study the properties of stacks of thin films of various materials obtaining the structure, magnetism and, roughness, etc. For soft matter e.g. polymer films and lipid layers with surfactants, the structure and the interfaces between these and solutions can be studied.