ICON: Imaging with Cold Neutrons
ICON is the cold neutron imaging facility at the neutron spallation source SINQ. The beamline offers specialized instrumentation for imaging with cold neutrons. The standard configuration allows radiography and tomography with field of view from 30mm to 250mm. An aperture wheel makes it possible to change beam intensity and collimation ratio. In addition to the standard setup it is possible to add beam modifying components for energy selective imaging and grating interferometry.
Due to the fact that cold neutrons have lower energies (longer wavelengths) than thermal neutrons the following points are the advantages of cold neutrons over thermal ones:
- Larger cross-sections for some elements and therefore higher sensitivity in thin layers.
- Phase contrast enhanced radiography works preferably with cold neutrons.
- Energy selective imaging to exploit the behavior near the Bragg edges of different materials.
Some characteristic numbers:
|Mean neutron energy||8.53 meV / 3.1Å|
|Neutron flux at sample position||1.3x107 neutrons cm-2 s-1 mA-1 (Aperture 20mm)|
|Max field of view||250 mm x 250 mm|
|Max resolution||20.3 μm|
Instrument reference: A. Kaestner et al., NIMA , 659(1), pp 387-393, doi:10.1016/j.nima.2011.08.022