The modelled field, Bz, is shown on the beam axis (black line) and at 160 mm from the axis (green line) in the horizontal plane. The readings of Hall probes situated at 160 mm from the beam axis are also shown. Vertical lines indicate the positions of the tracker stations (dashed lines) and the absorber (dotted line). The nominal r.m.s. beam width, σ(x), is calculated assuming a nominal input beam and using linear beam transport equations. See text for the description of the MICE apparatus. TOF0, TOF1 and TOF2 are time-of-flight detector stations; KL is a lead–scintillator pre-shower detector; EMR is the Electron–Muon Ranger.