HB2016 - List of Authors (Valishev, A.)

Paper

Title

Page

Suppression of Half-Integer Resonance in Fermilab Booster

1

V.A. Lebedev, A. Valishev
Fermilab, Batavia, Illinois, USA

The particle losses at injection in the FNAL Booster are one of the major factors limiting the machine performance. The losses are caused by motion non-linearity due to direct space charge and due to non-linearity introduced by large values of chromaticity sextupoles required to suppress transverse instabilities. The report aims to address the former - the suppression of incoherent space charge effects by reducing deviations from the perfect periodicity of linear optics functions. It should be achieved by high accuracy optics measurements with subsequent optics correction and by removing known sources of optics perturbations. The study shows significant impact of optics correction on the half-integer stop band with subsequent reduction of particle loss. We use realistic Booster lattice model to understand the present limitations, and investigate the possible improvements which would allow high intensity operation with PIP-II parameters.

MOPR035

Electron Lens for the Fermilab Integrable Optics Test Accelerator

1

G. Stancari, A.V. Burov, K. Carlson, D.J. Crawford, V.A. Lebedev, J.R. Leibfritz, M.W. McGee, S. Nagaitsev, L.E. Nobrega, C.S. Park, E. Prebys, A.L. Romanov, J. Ruan, V.D. Shiltsev, Y.-M. Shin, J.C.T. Thangaraj, A. Valishev
Fermilab, Batavia, Illinois, USA
D. Noll
IAP, Frankfurt am Main, Germany
Y.-M. Shin
Northern Illinois University, DeKalb, Illinois, USA

Funding: Fermilab is operated by Fermi Research Alliance, LLC, under Contract DE-AC02-07CH11359 with the US Department of Energy.
The Integrable Optics Test Accelerator (IOTA) is a research machine currently being designed and built at Fermilab. The research program includes the study of nonlinear integrable lattices, beam dynamics with self fields, and optical stochastic cooling. One section of the ring will contain an electron lens, a low-energy magnetized electron beam overlapping with the circulating beam. The electron lens can work as a nonlinear element, as an electron cooler, or as a space-charge compensator. We describe the physical principles, experiment design, and hardware implementation plans for the IOTA electron lens.

Poster MOPR035 [5.403 MB]

MOPR037

Space Charge Effects on Ion Beam Dynamics and Integrability in the Iota Ring

N.M. Cook, D.L. Bruhwiler, C.C. Hall, R.A. Kishek, S.D. Webb
RadiaSoft LLC, Boulder, Colorado, USA
A.L. Romanov, A. Valishev
Fermilab, Batavia, Illinois, USA

Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics under Award Number DE-SC0011340.
Modern hadron accelerators such as spallation sources and neutrino factories must push the intensity limits to meet increasingly challenging demands on performance. The Integrable Optics Test Accelerator (IOTA) is a small ring, currently under construction at Fermilab, which will explore advanced concepts in beam dynamics with low-energy proton beams with high space charge tune depression. Through use of a special nonlinear magnet insertion, large tune spread with amplitude can be achieved while preserving two integrals of motion for the single particle behavior. The stability of these invariants is particularly sensitive to collective effects such as space charge induced tune depression. We present results from simulations of IOTA using the particle-in-cell framework Warp and the accelerator simulation package Synergia exploring the behavior of proton beams in the presence of space charge. We examine potential lattice variations that correct for tune depression and beam mismatch while minimizing deviations from integrability.

MOPR038

Nonlinear Dynamics and Paths to Integrability in the IOTA Lattice

N.M. Cook, D.L. Bruhwiler, C.C. Hall, R.A. Kishek, S.D. Webb
RadiaSoft LLC, Boulder, Colorado, USA
A.L. Romanov, A. Valishev
Fermilab, Batavia, Illinois, USA

Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics under Award Number DE-SC0011340.
Betatron tune spread with amplitude suppresses intensity-driven parametric instabilities such as beam halo. Conventional approaches, such as using octupoles, can reduce the single-particle dynamic aperture. The concept of nonlinear integrable optics promises to introduce order unity tune spreads without introducing nonlinear resonances that limit the dynamic aperture. The idealized zero-current dynamics is constrained by two integrals of the motion, but even the single particle motion can be perturbed by energy spread. To study this concept, Fermilab is building the Integrable Optics Test Accelerator (IOTA). Simulations using the accelerator simulation package Synergia have demonstrated higher order effects to the ideal lattice, including effects due to finite phase advance across the nonlinear magnet and a particular sensitivity to chromaticity-correcting schemes. We present evidence for these higher-order effects, and illustrate the sensitivity of the dynamics to sextupole fields, showing that their proper pairing can preserve integrability and reduce beam loss.

Paper	Title	Page
MOPR034	Suppression of Half-Integer Resonance in Fermilab Booster	1
	V.A. Lebedev, A. Valishev Fermilab, Batavia, Illinois, USA
	The particle losses at injection in the FNAL Booster are one of the major factors limiting the machine performance. The losses are caused by motion non-linearity due to direct space charge and due to non-linearity introduced by large values of chromaticity sextupoles required to suppress transverse instabilities. The report aims to address the former - the suppression of incoherent space charge effects by reducing deviations from the perfect periodicity of linear optics functions. It should be achieved by high accuracy optics measurements with subsequent optics correction and by removing known sources of optics perturbations. The study shows significant impact of optics correction on the half-integer stop band with subsequent reduction of particle loss. We use realistic Booster lattice model to understand the present limitations, and investigate the possible improvements which would allow high intensity operation with PIP-II parameters.

MOPR035	Electron Lens for the Fermilab Integrable Optics Test Accelerator	1
	G. Stancari, A.V. Burov, K. Carlson, D.J. Crawford, V.A. Lebedev, J.R. Leibfritz, M.W. McGee, S. Nagaitsev, L.E. Nobrega, C.S. Park, E. Prebys, A.L. Romanov, J. Ruan, V.D. Shiltsev, Y.-M. Shin, J.C.T. Thangaraj, A. Valishev Fermilab, Batavia, Illinois, USA D. Noll IAP, Frankfurt am Main, Germany Y.-M. Shin Northern Illinois University, DeKalb, Illinois, USA
	Funding: Fermilab is operated by Fermi Research Alliance, LLC, under Contract DE-AC02-07CH11359 with the US Department of Energy. The Integrable Optics Test Accelerator (IOTA) is a research machine currently being designed and built at Fermilab. The research program includes the study of nonlinear integrable lattices, beam dynamics with self fields, and optical stochastic cooling. One section of the ring will contain an electron lens, a low-energy magnetized electron beam overlapping with the circulating beam. The electron lens can work as a nonlinear element, as an electron cooler, or as a space-charge compensator. We describe the physical principles, experiment design, and hardware implementation plans for the IOTA electron lens.
	Poster MOPR035 [5.403 MB]

MOPR037	Space Charge Effects on Ion Beam Dynamics and Integrability in the Iota Ring
	N.M. Cook, D.L. Bruhwiler, C.C. Hall, R.A. Kishek, S.D. Webb RadiaSoft LLC, Boulder, Colorado, USA A.L. Romanov, A. Valishev Fermilab, Batavia, Illinois, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics under Award Number DE-SC0011340. Modern hadron accelerators such as spallation sources and neutrino factories must push the intensity limits to meet increasingly challenging demands on performance. The Integrable Optics Test Accelerator (IOTA) is a small ring, currently under construction at Fermilab, which will explore advanced concepts in beam dynamics with low-energy proton beams with high space charge tune depression. Through use of a special nonlinear magnet insertion, large tune spread with amplitude can be achieved while preserving two integrals of motion for the single particle behavior. The stability of these invariants is particularly sensitive to collective effects such as space charge induced tune depression. We present results from simulations of IOTA using the particle-in-cell framework Warp and the accelerator simulation package Synergia exploring the behavior of proton beams in the presence of space charge. We examine potential lattice variations that correct for tune depression and beam mismatch while minimizing deviations from integrability.

MOPR038	Nonlinear Dynamics and Paths to Integrability in the IOTA Lattice
	N.M. Cook, D.L. Bruhwiler, C.C. Hall, R.A. Kishek, S.D. Webb RadiaSoft LLC, Boulder, Colorado, USA A.L. Romanov, A. Valishev Fermilab, Batavia, Illinois, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics under Award Number DE-SC0011340. Betatron tune spread with amplitude suppresses intensity-driven parametric instabilities such as beam halo. Conventional approaches, such as using octupoles, can reduce the single-particle dynamic aperture. The concept of nonlinear integrable optics promises to introduce order unity tune spreads without introducing nonlinear resonances that limit the dynamic aperture. The idealized zero-current dynamics is constrained by two integrals of the motion, but even the single particle motion can be perturbed by energy spread. To study this concept, Fermilab is building the Integrable Optics Test Accelerator (IOTA). Simulations using the accelerator simulation package Synergia have demonstrated higher order effects to the ideal lattice, including effects due to finite phase advance across the nonlinear magnet and a particular sensitivity to chromaticity-correcting schemes. We present evidence for these higher-order effects, and illustrate the sensitivity of the dynamics to sextupole fields, showing that their proper pairing can preserve integrability and reduce beam loss.