Vibrating wire field-measuring technique

The technique described here is dedicated to the problem of alignment of quadrupole magnets, a very important issue for particle accelerators. The technique is based on the excitation of the harmonics of a wire vibration by Lorenz forces between current in a wire and the surrounding magnetic field. Theoretical analyses show that knowing the amplitude and the phase of the various harmonics of the wire vibration, one can easily reconstruct the surrounding magnetic field which will indicate any misalignment of elements. Experiments confirmed the theoretical conclusions, and demonstrated the high sensitivity of the technique as well as its convenience for application.