Measurements of the five-dimensional phase space distribution of an intense ion beam

TL;DR

This paper presents a novel method for measuring a five-dimensional projection of an ion beam's phase space, revealing complex correlations and improving understanding of beam dynamics beyond previous 6D measurement limitations.

Contribution

It introduces a measurement technique using three slits and one screen to capture 5D phase space projections, enabling better analysis of intense ion beams.

Findings

Revealed nonlinear transverse-longitudinal correlations in the beam core.

Compared measured 5D distributions with particle-in-cell simulations.

Discussed potential for reconstructing full 6D phase space from lower-dimensional projections.

Abstract

No simulation of intense beam transport has accurately reproduced measurements at the level of beam halo. One potential explanation of this discrepancy is a lack of knowledge of the initial distribution of particles in six-dimensional (6D)~phase space. A direct 6D measurement of an ion beam was recently performed at the Spallation Neutron Source (SNS) Beam Test Facility (BTF), revealing nonlinear transverse-longitudinal correlations in the beam core that affect downstream evolution. Unfortunately, direct 6D~measurements are limited in resolution and dynamic range; here, we discuss the use of three slits and one screen to measure a 5D projection of the 6D phase space distribution, overcoming these limitations at the cost of one dimension. We examine the measured 5D distribution before and after transport through the BTF and compare to particle-in-cell simulations. We also discuss the possibility of reconstructing the 6D distribution from 5D and 4D projections.