IPAC2019 - List of Authors (Edelen, J.P.)

Paper	Title	Page
WEPTS068	A Novel S-Based Symplectic Algorithm for Tracking With Space Charge	3279
	J.P. Edelen, D.T. Abell, D.L. Bruhwiler, N.M. Cook, C.C. Hall, S.D. Webb RadiaSoft LLC, Boulder, Colorado, 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 Traditional finite-difference particle-in-cell methods for modeling self-consistent space charge introduce non-Hamiltonian effects that make long-term tracking in storage rings unreliable. Foremost of these is so-called grid heating. Particularly for studies where the Hamiltonian invariants are critical for understanding the beam dynamics, such as nonlinear integrable optics, these spurious effects make interpreting simulation results difficult. To remedy this, we present a novel symplectic spectral space charge algorithm that is free of non-Hamiltonian numerical effects and, therefore, suitable for long-term tracking studies. Results presented here include a detailed study of the solver’s performance under a range of conditions. First, we show benchmarking and convergence studies for different particle shapes and different particle distributions. Then we demonstrate the solver’s ability to preserve Hamiltonian structure by studying the formation of space-charge driven resonances using both our algorithm and traditional PIC.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS068
About •	paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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WEPTS070	First Measurements of Nonlinear Decoherence in the IOTA Ring	3286
	C.C. Hall, D.L. Bruhwiler, J.P. Edelen RadiaSoft LLC, Boulder, Colorado, USA N. Kuklev University of Chicago, Chicago, Illinois, USA A.L. Romanov, A. Valishev Fermilab, Batavia, Illinois, USA
	Funding: This work has been supported by the U.S. Department of Energy Office of Science, Office of High Energy Physics under Award No. DE-SC00111340 The Integrable Optics Test Accelerator (IOTA), at Fermi National Laboratory is aimed at testing nonlinear optics for the next generation of high intensity rings. Through use of a special magnetic element the ring is designed to induce a large tune spread with amplitude while maintaining integrable motion. This will allow for the suppression of instabilities in high-intensity beams without significant reduction in dynamic aperture. One important aspect of this is the nonlinear decoherence that occurs when a beam is injected off axis or receives a transverse kick while circulating in the ring. This decoherence has been studied in detail, with simulations, for protons in IOTA both with and without space-charge. However, it has yet to be demonstrated experimentally. During the first phase of the IOTA experimental program, the ring is operated with 100 MeV electrons, allowing for the study of nonlinear optics without the complications introduced by space charge. Here we present measurements taken during the IOTA commissioning, and an analysis of the results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS070
About •	paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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THPMP047	Advanced Modeling and Optimization of Thermionic Energy Converters	3552
	J.P. Edelen, N.M. Cook, C.C. Hall, Y. Hu RadiaSoft LLC, Boulder, Colorado, USA J.-L. Vay LBNL, Berkeley, California, 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-SC0017162 Thermionic energy converters (TEC) are a class of thermoelectric devices, which promise improvements to the efficiency and cost of both small- and large-scale electricity generation. A TEC is comprised of a narrowly-separated thermionic emitter and an anode. Simple structures are often space-charge limited as operating temperatures produce currents exceeding the Child-Langmuir limit. We present results from 3D simulations of these devices using the particle-in-cell code Warp, developed at Lawrence Berkeley National Lab. We demonstrate improvements to the Warp code permitting high fidelity simulations of complex device geometries. These improvements include modeling of non-conformal geometries using mesh refinement and cut-cells with a dielectric solver, in addition to importing geometries directly from standard CAD output. In this paper we showcase some of these new features and demonstrate their use.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP047
About •	paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

A Novel S-Based Symplectic Algorithm for Tracking With Space Charge

3279

J.P. Edelen, D.T. Abell, D.L. Bruhwiler, N.M. Cook, C.C. Hall, S.D. Webb
RadiaSoft LLC, Boulder, Colorado, 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
Traditional finite-difference particle-in-cell methods for modeling self-consistent space charge introduce non-Hamiltonian effects that make long-term tracking in storage rings unreliable. Foremost of these is so-called grid heating. Particularly for studies where the Hamiltonian invariants are critical for understanding the beam dynamics, such as nonlinear integrable optics, these spurious effects make interpreting simulation results difficult. To remedy this, we present a novel symplectic spectral space charge algorithm that is free of non-Hamiltonian numerical effects and, therefore, suitable for long-term tracking studies. Results presented here include a detailed study of the solver’s performance under a range of conditions. First, we show benchmarking and convergence studies for different particle shapes and different particle distributions. Then we demonstrate the solver’s ability to preserve Hamiltonian structure by studying the formation of space-charge driven resonances using both our algorithm and traditional PIC.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS068

About •

paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPTS070

First Measurements of Nonlinear Decoherence in the IOTA Ring

3286

C.C. Hall, D.L. Bruhwiler, J.P. Edelen
RadiaSoft LLC, Boulder, Colorado, USA
N. Kuklev
University of Chicago, Chicago, Illinois, USA
A.L. Romanov, A. Valishev
Fermilab, Batavia, Illinois, USA

Funding: This work has been supported by the U.S. Department of Energy Office of Science, Office of High Energy Physics under Award No. DE-SC00111340
The Integrable Optics Test Accelerator (IOTA), at Fermi National Laboratory is aimed at testing nonlinear optics for the next generation of high intensity rings. Through use of a special magnetic element the ring is designed to induce a large tune spread with amplitude while maintaining integrable motion. This will allow for the suppression of instabilities in high-intensity beams without significant reduction in dynamic aperture. One important aspect of this is the nonlinear decoherence that occurs when a beam is injected off axis or receives a transverse kick while circulating in the ring. This decoherence has been studied in detail, with simulations, for protons in IOTA both with and without space-charge. However, it has yet to be demonstrated experimentally. During the first phase of the IOTA experimental program, the ring is operated with 100 MeV electrons, allowing for the study of nonlinear optics without the complications introduced by space charge. Here we present measurements taken during the IOTA commissioning, and an analysis of the results.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS070

About •

paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPMP047

Advanced Modeling and Optimization of Thermionic Energy Converters

3552

J.P. Edelen, N.M. Cook, C.C. Hall, Y. Hu
RadiaSoft LLC, Boulder, Colorado, USA
J.-L. Vay
LBNL, Berkeley, California, 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-SC0017162
Thermionic energy converters (TEC) are a class of thermoelectric devices, which promise improvements to the efficiency and cost of both small- and large-scale electricity generation. A TEC is comprised of a narrowly-separated thermionic emitter and an anode. Simple structures are often space-charge limited as operating temperatures produce currents exceeding the Child-Langmuir limit. We present results from 3D simulations of these devices using the particle-in-cell code Warp, developed at Lawrence Berkeley National Lab. We demonstrate improvements to the Warp code permitting high fidelity simulations of complex device geometries. These improvements include modeling of non-conformal geometries using mesh refinement and cut-cells with a dielectric solver, in addition to importing geometries directly from standard CAD output. In this paper we showcase some of these new features and demonstrate their use.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP047

About •

paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)