Simulations have been done for many configurations of the coils that guide the precession through the instrument. For the SESANS mode these coils need to be in a magnetic balance for the full beam cross section. This is not trivial because of all the spacial restrictions in the instrument. On the left one can see the SESANS configuration (all coils in line) with a coil for the first arm, sample position and second arm. On the right one can see the magnetic field on the central axis of the instrument. Below a colorful plot of this field for the full setup.
