The impact of high-dimensional phase space correlations on the beam dynamics in a linear accelerator

TL;DR

This paper investigates how high-dimensional phase space correlations affect beam dynamics in linear accelerators, showing that decorrelation impacts early acceleration but low-dimensional projections may suffice for predictions.

Contribution

It provides an analysis of the effects of artificial decorrelation on beam dynamics and demonstrates the convergence of correlated and decorrelated distributions during early acceleration.

Findings

Decorrelated twin distributions converge early in acceleration.

Low-dimensional projections may be adequate for detailed predictions.

Artificial decorrelation influences beam evolution in linacs.

Abstract

Hadron beams develop intensity-dependent transverse-longitudinal correlations within radio-frequency quadrupole (RFQ) accelerating structures. These correlations are only visible in six-dimensional phase space and are destroyed by reconstructions from low-dimensional projections. In this work, we estimate the effect of artificial decorrelation on the beam dynamics in the Spallation Neutron Source (SNS) linac and Beam Test Facility (BTF). We show that the evolution of a realistic initial distribution and its decorrelated twin converge during the early acceleration stages; thus, low-dimensional projections are probably sufficient for detailed predictions in high-power linacs.