MEASURING MULTIPOLE FIELD ERRORS IN MAGNET APERTURES OF LARGE ASPECT RATIO BY MEANS OF AN OSCILLATING WIRE ON ELLIPTIC TRAJECTORIES

P. Arpaia, C. Petrone, S. Russenschuck
Abstract:
Errors in the transversal field of accelerator magnets are usually expressed in terms of the coefficients of a harmonic expansion on a circular trajectory in the magnet’s aperture.
An elliptic trajectory more suited to apertures with large width-to-height ratios allows the field inside the domain to be reconstructed with a higher accuracy. Displacing an oscillating wire along an elliptical trajectory and acquiring the amplitude of the wire oscillation at each point yield a periodic signal to be expanded into the elliptic multipoles. The paper discusses the theoretical background, the practical implementation in the measurement system, and the accuracy achieved in the measurements of a quadrupole magnet.
Keywords:
magnetic measurements, accelerator magnet, multipole field expansions
Download:
IMEKO-WC-2012-TC4-O13.pdf
DOI:
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Event details
Event name:
XX IMEKO World Congress
Title:

Metrology for Green Growth

Place:
Busan, REPUBLIC of KOREA
Time:
09 September 2012 - 12 September 2012