JAVIER REYNA
Happy. Engineer. Designer.
One of four magnet-carrying modules used in the particle accelerator. Magnets are placed inside the empty gaps once they have been carefully measured and the desired magnetic field has been obtained.
Prototype Setup: A single wire is stretched across a desired length, which passes through two photo photo interrupters, and over a magnet.
With the vibrating wire method, a single stretched wire is placed in close proximity to the magnet of interest and has a range of frequencies applied to it until achieving vibrations at resonance. Since the presence of a magnetic field and a current through the wire cause the wire to vibrate, we can model the vibration as standing waves. This allows us to back out the position of the magnet and the strength of the magnetic field by analyzing the harmonic responses of the wire.
The resonance effect greatly increases the sensitivity of the measurement device and allows position detection at the micron level. The more harmonics used, the greater the accuracy of the method. For instance, the figure on the right indicates that the magnet was located about 18 inches from the sensor. This ultimately enables us to detect magnetic fields in small gaps and allows us to determine the location of misalignments along undulators thanks to its high sensitivity, which increases proportional to the number of harmonics used.
Magnetic Field Reconstruction from the First 10 Harmonics
The individual harmonic waves, shown in blue, were summed to net the reconstructed magnetic field, represented by the black line. The misaligned magnet is located at x = 18in.