The magnet is the UA1 dipole currently being used in NOMAD
(Fig. 10).
It has an inner field volume of 
.
It provides a horizontal field of up to 0.7 T in a direction perpendicular
to the neutrino beam.
The magnet consists of mirror-image halves (the plane of symmetry is a
vertical plane containing the beam direction) which open on a system of
rails to give access to the detector. Each half consists of 8 iron C's, providing the return
path for the magnetic field, and one water cooled aluminium coil.
Each C is 87.5 cm long along the beam and successive C's are separated
from each other by 80 mm gaps.
Figure:
The UA1 magnet with the detector elements inserted for this experiment.