Proton beam dynamics in bare IOTA with intense space-charge

TL;DR

This paper models proton beam dynamics in the IOTA accelerator under intense space-charge conditions, comparing simulation codes to predict emittance growth and beam loss.

Contribution

It provides a comparative analysis of space-charge simulation models in predicting proton beam behavior in the IOTA accelerator.

Findings

Agreement within a factor of 2 in core phase-space density predictions

Significant differences in tail distributions and beam loss predictions

Simulations remain consistent over 100 synchrotron periods at moderate currents

Abstract

We are commissioning a 2.5-MeV proton beam for the Integrable Optics Test Accelerator at Fermilab, allowing experiments in the strong space-charge regime with incoherent betatron tune shifts nearing 0.5. Accurate modelling of space-charge dynamics is vital for understanding planned experiments. We compare anticipated emittance growth and beam loss in the bare IOTA configuration using transverse space-charge models in Xsuite, PyORBIT, and MADX simulation codes. Our findings reveal agreement within a factor of 2 in core phase-space density predictions up to 100 synchrotron periods at moderate beam currents, while tail distributions and beam loss show significant differences.