In this thesis I have explored the challenges of long guides and instrumentation for the long pulsed European Spallation Source. I have derived the theory needed for quantifying the performance of a guide using brilliance transfer. With this tool it is easier to objectively compare how well different guides perform the same task.In comparing different guide geometries, I have shown that for transporting thermal or
highly divergent neutrons over medium to long distances, elliptic and parabolic guides are significantly better in terms of brilliance transfer than simpler guides. I have also shown that the transport of a neutron beam over a very long distance is quite feasible,even for highly divergent, thermal neutrons.
I have investigated various methods for blocking the direct line of sight between the
neutron source and the sample area, in order to reduce the fast neutron background.
I have shown that doing this is feasible, even for advanced guide geometries, such as elliptic and parabolic guides. I have also looked into how guide imperfections affect the brilliance transfer, and shown that long elliptic guide are robust against imperfections at the levels we expect to see.
I have also detailed the simulations and optimisations of one particular instrument,
the Compact SANS, on which I have worked on the design of the guide, collimation,
and chopper systems.