Eddy currents in accelerator magnets

TL;DR

This paper analyzes eddy current effects in accelerator magnets, including field modifications and power losses, providing theoretical insights, numerical and experimental comparisons, and design guidelines to mitigate these effects.

Contribution

It offers a comprehensive analysis combining Maxwell-based theory, numerical simulations, measurements, and practical design recommendations for eddy current effects in accelerator magnets.

Findings

Derived formulas for estimating eddy current effects.

Comparison of theoretical, numerical, and measured results.

Design recommendations to minimize eddy currents.

Abstract

This paper covers the main eddy current effects in accelerator magnets - field modification (time delay and field quality) and resistive power losses. In the first part, starting from the Maxwell equations, a basic understanding of the processes is given and explained with examples of simple geometry and time behaviour. Useful formulas are derived for an analytic estimate of the size of the effects. In the second part the effects in real magnets are analysed and described in comparison with numerical and measured results. Finally, based on the previous parts, design recommendations are given regarding how to minimize eddy current effects.