Design and Performance of a Novel Low Energy Multi-Species Beamline for the ALPHA Antihydrogen Experiment

TL;DR

This paper presents the design, optimization, and initial performance evaluation of a new low-energy multi-species beamline for the ALPHA antihydrogen experiment at CERN, achieving high particle transfer efficiency.

Contribution

It introduces a novel beamline design optimized through combined analytical and numerical methods, validated with experimental data for efficient low-energy particle transport.

Findings

High transfer efficiency for antiprotons and positrons

Successful validation of models with experimental data

Effective beamline design for antihydrogen experiments

Abstract

The ALPHA Collaboration, based at the CERN Antiproton Decelerator, has recently implemented a novel beamline for low-energy ($\lesssim$ 100 eV) positron and antiproton transport between cylindrical Penning traps that have strong axial magnetic fields. Here, we describe how a combination of semianalytical and numerical calculations were used to optimise the layout and design of this beamline. Using experimental measurements taken during the initial commissioning of the instrument, we evaluate its performance and validate the models used for its development. By combining data from a range of sources, we show that the beamline has a high transfer efficiency, and estimate that the percentage of particles captured in the experiments from each bunch is (78 $\pm$ 3)% for up to $10^{5}$ antiprotons, and (71 $\pm$ 5)% for bunches of up to $10^{7}$ positrons.