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Main Authors:	Evans, Nicholas J., Hoover, Austin, Gorlov, Timofey, Morozov, Vasiliy
Format:	Preprint
Published:	2026
Subjects:	Accelerator Physics Applied Physics
Online Access:	https://arxiv.org/abs/2601.13517
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author	Evans, Nicholas J. Hoover, Austin Gorlov, Timofey Morozov, Vasiliy
author_facet	Evans, Nicholas J. Hoover, Austin Gorlov, Timofey Morozov, Vasiliy
contents	Multi-turn charge-exchange injection is the primary method of creating high-intensity hadron beams in circular accelerators, and phase space painting during injection enables tailoring of the accumulated phase space distribution. A technique we call eigenpainting allows injection of particles into a single mode of a coupled ring, providing full four-dimensional control of the phase space distribution. Under ideal conditions, uniform eigenpainting generates a linear-force equilibrium distribution in the transverse plane, with zero volume in four-dimensional transverse phase space, even including space charge. We have implemented eigenpainting for the first time in the Spallation Neutron Source (SNS) Accumulator Ring. Injecting 8.8 $μ$C of 800 MeV beam, we obtain a final ratio of intrinsic transverse emittances of $\approx$2.4. We analyze the effect of space charge on the final distribution through comparison of the reconstructed phase space to particle-in-cell simulations.
format	Preprint
id	arxiv_https___arxiv_org_abs_2601_13517
institution	arXiv
publishDate	2026
record_format	arxiv
spellingShingle	Demonstration of a novel phase space painting method in a coupled lattice to mitigate space charge in high-intensity hadron beams Evans, Nicholas J. Hoover, Austin Gorlov, Timofey Morozov, Vasiliy Accelerator Physics Applied Physics Multi-turn charge-exchange injection is the primary method of creating high-intensity hadron beams in circular accelerators, and phase space painting during injection enables tailoring of the accumulated phase space distribution. A technique we call eigenpainting allows injection of particles into a single mode of a coupled ring, providing full four-dimensional control of the phase space distribution. Under ideal conditions, uniform eigenpainting generates a linear-force equilibrium distribution in the transverse plane, with zero volume in four-dimensional transverse phase space, even including space charge. We have implemented eigenpainting for the first time in the Spallation Neutron Source (SNS) Accumulator Ring. Injecting 8.8 $μ$C of 800 MeV beam, we obtain a final ratio of intrinsic transverse emittances of $\approx$2.4. We analyze the effect of space charge on the final distribution through comparison of the reconstructed phase space to particle-in-cell simulations.
title	Demonstration of a novel phase space painting method in a coupled lattice to mitigate space charge in high-intensity hadron beams
topic	Accelerator Physics Applied Physics
url	https://arxiv.org/abs/2601.13517

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