Optimization of low aspect ratio, iron dominated dipole magnets

N Majernik,J B Rosenzweig,W P Leemans,J Van Tilborg,S K Barber

doi:10.1103/physrevaccelbeams.22.032401

Abstract

Author(s): Majernik, N; Barber, SK; Van Tilborg, J; Rosenzweig, JB; Leemans, WP | Abstract: A study of the optimization of iron dominated dipole magnets with pole face widths comparable or less than the gap size, i.e., low aspect ratio (AR), is conducted using both theoretical and computational approaches. This regime of magnet design is particularly relevant in the context of laser plasma accelerators (LPA) due to unique beam parameters and geometric constraints, namely large energy spreads and the requirement for large apertures to accommodate drive laser passage. The breakdown of commonly employed approximations and rules of thumb in typical AR1 magnet design is examined. A library of generalized, optimized pole face geometries is provided to expedite optimization of future magnets. Finally, this methodology is used to design an electromagnetic chicane which has been fabricated, validated, and is currently in use in an x-ray free electron laser driven LPA experiment at LBNL.

Highlights

Many disciplines employ dipole magnets, often requiring a consistent, flat field over some volume of interest
A study of the optimization of iron dominated dipole magnets with pole face widths comparable or less than the gap size, i.e., low aspect ratio (AR), is conducted using both theoretical and computational approaches. This regime of magnet design is relevant in the context of laser plasma accelerators (LPA) due to unique beam parameters and geometric constraints, namely large energy spreads and the requirement for large apertures to accommodate drive laser passage
Better performance is indicated by points which are lower and further to the right

Summary

Introduction

Many disciplines employ dipole magnets, often requiring a consistent, flat field over some volume of interest. This work will discuss the optimization of field quality for a fixed magnet size where the gap between the pole faces is of the same order as the width of the pole face—the case of low aspect ratio.

Methods

Results

Conclusion