Transverse emittance measurement in 2D and 4D performed on a Low Energy Beam Transport line: benchmarking and data analysis

TL;DR

This paper compares 2D and 4D transverse emittance measurement techniques on a low-energy ion beam, analyzing their accuracy, advantages, drawbacks, and introducing a new data analysis method for improved results.

Contribution

It provides a comprehensive benchmark of two common emittance scanners, discusses measurement challenges, and proposes a novel data analysis approach for better emittance characterization.

Findings

Comparison of measurement accuracy and limitations of the two emittance scanners.

Identification of noise and aberration effects on low-density beam measurements.

Introduction of a new data analysis method improving emittance figure reconstruction.

Abstract

2D and 4D transverse phase-space of a low-energy ion-beam is measured with two of the most common emittance scanners. The article covers the description of the installation, the setup, the settings, the experiment and the benchmark of the two emittance meters. We compare the results from three series of measurements and present the advantages and drawbacks of the two systems. Coupling between phase-space planes, correlations and mitigation of deleterious effects are discussed. The influence of background noise and aberrations of trace-space figures on emittance measurements and RMS calculations is highlighted, especially for low density beams and halos. A new data analysis method using noise reduction, filtering, and reconstruction of the emittance figure is described. Finally, some basic concepts of phase-space theory and application to beam transport are recalled.