Measuring field multipoles in accelerator magnets with small-apertures by an oscillating wire moved on a circular trajectory

作者：Arpaia P^*; Buzio M; Perez J Garcia; Petrone C; Russenschuck S; Walckiers L

来源：Journal of Instrumentation, 2012, 7: P05003.

DOI：10.1088/1748-0221/7/05/P05003

• Instrumentation for particle accelerators and storage rings - high energy (linear accelerators, synchrotrons)
• Acceleration cavities and magnets superconducting (high-temperature superconductor
• radiation hardened magnets
• normal-conducting
• permanent magnet devices
• wigglers and undulators)
• Data processing methods
• Accelerator Subsystems and Technologies

A method based on an oscillating wire for measuring the field quality in accelerator magnets with small apertures of the order of 10 mm is proposed. The wire is positioned step-by-step on the generators of a cylindrical domain inside the magnet aperture, i.e. its end-points at the stages are moved on a circular trajectory. The amplitudes of the wire's forced oscillations are measured and related to field harmonics by a suitable analytical model. In this paper, the analytical model, the measurement procedure, and the measurement system architecture of the oscillating wire method are presented. The method is validated by comparison with the standard rotating-coil system. A case study on small-aperture, permanent-magnet quadrupoles constructed for the Linac4 injector at CERN is illustrated.

• 出版日期2012-5