Characterization and Tuning of Ultra High Gradient Permanent Magnet Quadrupoles

TL;DR

This paper introduces a new tuning scheme for ultra high gradient permanent magnet quadrupoles, enabling precise control of field components and achieving gradients up to 500 T/m with minimized aperture sizes.

Contribution

A novel performance control and tuning method for high gradient quadrupoles that reduces higher order field components and improves aperture size matching.

Findings

Achieved field gradients up to 500 T/m.

Validated characterization method with electron beam at Mainz Microtron MAMI.

Reduced higher order multipole components for better beam quality.

Abstract

The application of quadrupole-devices with high field gradients and small apertures requires precise control over higher order multipole field components. We present a new scheme for performance control and tuning, which allows the illumination of most of the quadrupole-device aperture because of the reduction of higher order field components. Consequently, the size of the aperture can be minimized to match the beam size achieving field gradients of up to 500 T/m at good imaging quality. The characterization method based on a Hall probe measurement and a Fourier analysis was confirmed using the high quality electron beam at the Mainz Microtron MAMI.