Magnet alignment monitoring system with eigenfrequency-based wire sag correction
Open Access
- 12 February 2021
- journal article
- research article
- Published by IOP Publishing in Measurement Science and Technology
- Vol. 32 (7), 075009
- https://doi.org/10.1088/1361-6501/abe5e4
Abstract
The precision of magnet alignment in next-generation light sources is critical. To achieve this, the multipole magnets on a common girder of SPring-8-II, an upgrade of SPring-8, are planned to be aligned using the vibrating-wire technique. We developed an alignment monitoring system to monitor the magnet positions in the tunnel where the vibrating-wire technique cannot be executed while the magnets are not energized or exist with vacuum chambers. The alignment monitoring system utilizes a non-contact capacitive sensor embedded in a ceramic ball to measure the wire position relative to the center of the ball and derives the wire sag by measuring a higher mode eigenfrequency. The constitution of this system is illustrated for relevant studies, including the investigation of wire sag against the eigenfrequency, observation of the actual wire sag at a test bench, and validation of the system on the girders for the prototype magnets of SPring-8-II. The system measured the positions of a series of magnets with a precision of ±4 µm (peak to peak) in a 4 m range, both in the horizontal and vertical directions, meeting the requirement of SPring-8-II.Keywords
This publication has 5 references indexed in Scilit:
- Performance verification of a precise vibrating-wire magnet alignment technique for next-generation light sourcesReview of Scientific Instruments, 2019
- Engineering survey planning for the alignment of a particle accelerator: part I. Proposition of an assessment methodMeasurement Science and Technology, 2017
- Stretched wire measurement of multipole accelerator magnetsPhysical Review Special Topics - Accelerators and Beams, 2012
- Vibrating wire field-measuring techniqueNuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1997
- An analysis of the reduction of the sensitivity to magnet misalignment in low emittance synchrotron radiation sources by unifying the magnets in each straight sectionNuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1992