In this page, we are looking to harvest information about calibrations that are performed at neutron reflectometry instruments. For a given calibration, please include the following information:

  • What is being calibrated?
  • How is the calibration performed?
  • An example of the calibrated data and details of how you get this information
  • References/Code for the above would be great!

Once you add your calibration, please include yourself in the authors of this page.

Things to get you thinking: (if you calibrate/measure something not on this list then please let us know)

  1. How do you measure the total flux of your beamline?
  2. How do you measure the TOF flight distance of your beamline with neutrons (and without?) Neutron TOF only
  3. How do you measure the wavelength or wavelengths of your beamline? Similar to 2 but for monochromatic beamlines.
  4. How do you measure the polarisation of your beamline? (TOF, monochromatic)
  5. How do you check with a non-magnetic sample you get zero magnetic response with polarised neutrons, i.e your zero is zero, and to what precision? (TOF/Mono)
  6. If you have a pixelated detector. How do you measure your detector corrections to then flatten the detector response? (i.e. Correct all pixels to have a similar response, this is sometimes referred to as a flood measurement)
  7. If you have a pixelated detector how do you measure the pixel positions (often called a detector map)
  8. How do your scan your slit gaps and positions (bit brain dead this one but everyone has to do it)
  9. How do you measure the feathering function for the moderator (I know this is a TOF source thing at pulses sources)
  10. How do you measure the resolution function for your beamline.
  11. How do you measure the background levels for your beamline. Lots of things here (dark/quiet counts for detector noise, instrument background from cosmic noise, incoherent background during a reflectivity measurement from samples etc.)
  12. How do you calibrate your angle stages to ensure that when you move a degree they move a degree.
  13. How do you label your polarisation states?
  14. How do you measure the lateral coherence length of the beamline. (important for offspecular scattering, or if you have partial surface coverage; 10.1103/PhysRevA.89.033851)
  15. How do you measure guide structure. Using pinhole camera setup. Plus a special neutron camera. See Platypus paper

Frequent Calibration Examples

Infrequent Calibration Examples

  • Time-of-flight distance