IPAC2014 - List of Authors (Batygin, Y.K.)

Paper	Title	Page
TUOAB03	Nonlinear Optics for Suppression of Halo Formation in Space Charge Dominated Beams	953
	Y.K. Batygin, A. Scheinker LANL, Los Alamos, New Mexico, USA C. Li IMP, Lanzhou, People's Republic of China
	Traditional accelerator designs utilize linear focusing elements (quadrupoles, solenoids) to provide stable particle motion. High – intensity rms - matched non - uniform beams are intrinsically mismatched with linear focusing structure. It results in space charge induced beam emittance growth and halo formation, which can be suppressed in a quadrupole channel with higher-order multipole field components. In this paper, overview of FODO quadrupole channels with arbitrary multipoles is given. Effective averaged potential is presented for the structure with periodic combination of multipole lenses and quadrupoles. Density of matched beam avoiding emittance growth and halo formation is derived. Performed analysis allows matching of realistic beam with the internal structure of the focusing field. Beam dynamics studies with suppressed halo are presented and discussed.
	Slides TUOAB03 [3.404 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUOAB03
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THPRO094	Large Scale Particle Tracking and the Application in the Simulation of the RFQ Accelerator	3107
	L. Du, Q.Z. Xing TUB, Beijing, People's Republic of China Y.K. Batygin LANL, Los Alamos, New Mexico, USA Y. He, L. Yang IMP, Lanzhou, People's Republic of China J. Xu, R. Zhao IS, Beijing, People's Republic of China
	Large scale particle tracking is important for the design and optimization of the Radio-frequency Quadrupole (RFQ) accelerator. In this paper, we present RFQ simulation results of new parallel software named LOCUS3D, which is developed at Institute of Software, Chinese Academy of Sciences. It is based on Particle-In-Cell method and calculates three-dimensional space charge field by an efficient parallel fast Fourier transform method. A RFQ accelerator in Tsinghua University is simulated by tracking 100 million macro particles. This RFQ is designed to accelerate protons from 50 keV to 3 MeV, with peak beam current of 50 mA. As large number of particles been simulated, more accurate and detailed information have been obtained.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO094
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THPRO097	Space-charge Neutralization of 750-keV H⁻ Beam at LANSCE	3116
	Y.K. Batygin, C. Pillai, L. Rybarcyk LANL, Los Alamos, New Mexico, USA
	The injector part of Los Alamos Neutron Science Center (LANSCE) includes 750-keV H⁻ beam transport located upstream of the Drift Tube Linac. Space charge effects play an important role in the beam transport therein. A series of experiments were performed to determine the level of beam space charge neutralization, and time required for neutralization. Measurements performed at different places along the structure indicate significant variation of neutralized space charge beam dynamics along the beamline. Results of measurements were compared with numerical simulations using macroparticle method and envelope equations to determine values of the effective beam current after neutralization, and effective beam emittance, required for beam tuning.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO097
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THPRO098	Realistic Modeling of 4-Rod RFQs with CST Studio	3119
	S.S. Kurennoy, Y.K. Batygin, E.R. Olivas, L. Rybarcyk LANL, Los Alamos, New Mexico, USA
	RFQ accelerators are usually designed and modeled with standard codes based on electrostatic field approximations. There are recent examples when this approach fails to predict the RFQ performance accurately: for 4-rod RFQs 3D effects near the vane ends can noticeably influence the beam dynamics. The same applies to any RFQ where the quadrupole symmetry is broken, e.g., 4-vane RFQ with windows. We analyzed two 201.25-MHz 4-rod RFQs – one recently commissioned at FNAL and a new design for LANL – using 3D modeling with CST Studio. In both cases the manufacturer CAD RFQ model was imported into CST. The EM analysis with MicroWave Studio (MWS) was followed by beam dynamics modeling with Particle Studio (PS). For the LANL RFQ with duty factor up to 15%, a thermal-stress analysis with ANSYS was also performed. The simulation results for FNAL RFQ helped our Fermilab colleagues fix the low output beam energy. The LANL RFQ design was modified after CST simulations indicated insufficient tuning range and incorrect output energy; the modified version satisfies the design requirements. Our PS results were confirmed by multi-particle beam-dynamics codes that used the MWS-calculated RF fields.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO098
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Paper

Title

Page

Nonlinear Optics for Suppression of Halo Formation in Space Charge Dominated Beams

953

Y.K. Batygin, A. Scheinker
LANL, Los Alamos, New Mexico, USA
C. Li
IMP, Lanzhou, People's Republic of China

Traditional accelerator designs utilize linear focusing elements (quadrupoles, solenoids) to provide stable particle motion. High – intensity rms - matched non - uniform beams are intrinsically mismatched with linear focusing structure. It results in space charge induced beam emittance growth and halo formation, which can be suppressed in a quadrupole channel with higher-order multipole field components. In this paper, overview of FODO quadrupole channels with arbitrary multipoles is given. Effective averaged potential is presented for the structure with periodic combination of multipole lenses and quadrupoles. Density of matched beam avoiding emittance growth and halo formation is derived. Performed analysis allows matching of realistic beam with the internal structure of the focusing field. Beam dynamics studies with suppressed halo are presented and discussed.

Slides TUOAB03 [3.404 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUOAB03

Export •

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

THPRO094

Large Scale Particle Tracking and the Application in the Simulation of the RFQ Accelerator

3107

L. Du, Q.Z. Xing
TUB, Beijing, People's Republic of China
Y.K. Batygin
LANL, Los Alamos, New Mexico, USA
Y. He, L. Yang
IMP, Lanzhou, People's Republic of China
J. Xu, R. Zhao
IS, Beijing, People's Republic of China

Large scale particle tracking is important for the design and optimization of the Radio-frequency Quadrupole (RFQ) accelerator. In this paper, we present RFQ simulation results of new parallel software named LOCUS3D, which is developed at Institute of Software, Chinese Academy of Sciences. It is based on Particle-In-Cell method and calculates three-dimensional space charge field by an efficient parallel fast Fourier transform method. A RFQ accelerator in Tsinghua University is simulated by tracking 100 million macro particles. This RFQ is designed to accelerate protons from 50 keV to 3 MeV, with peak beam current of 50 mA. As large number of particles been simulated, more accurate and detailed information have been obtained.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO094

Export •

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

THPRO097

Space-charge Neutralization of 750-keV H⁻ Beam at LANSCE

3116

Y.K. Batygin, C. Pillai, L. Rybarcyk
LANL, Los Alamos, New Mexico, USA

The injector part of Los Alamos Neutron Science Center (LANSCE) includes 750-keV H⁻ beam transport located upstream of the Drift Tube Linac. Space charge effects play an important role in the beam transport therein. A series of experiments were performed to determine the level of beam space charge neutralization, and time required for neutralization. Measurements performed at different places along the structure indicate significant variation of neutralized space charge beam dynamics along the beamline. Results of measurements were compared with numerical simulations using macroparticle method and envelope equations to determine values of the effective beam current after neutralization, and effective beam emittance, required for beam tuning.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO097

Export •

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

THPRO098

Realistic Modeling of 4-Rod RFQs with CST Studio

3119

S.S. Kurennoy, Y.K. Batygin, E.R. Olivas, L. Rybarcyk
LANL, Los Alamos, New Mexico, USA

RFQ accelerators are usually designed and modeled with standard codes based on electrostatic field approximations. There are recent examples when this approach fails to predict the RFQ performance accurately: for 4-rod RFQs 3D effects near the vane ends can noticeably influence the beam dynamics. The same applies to any RFQ where the quadrupole symmetry is broken, e.g., 4-vane RFQ with windows. We analyzed two 201.25-MHz 4-rod RFQs – one recently commissioned at FNAL and a new design for LANL – using 3D modeling with CST Studio. In both cases the manufacturer CAD RFQ model was imported into CST. The EM analysis with MicroWave Studio (MWS) was followed by beam dynamics modeling with Particle Studio (PS). For the LANL RFQ with duty factor up to 15%, a thermal-stress analysis with ANSYS was also performed. The simulation results for FNAL RFQ helped our Fermilab colleagues fix the low output beam energy. The LANL RFQ design was modified after CST simulations indicated insufficient tuning range and incorrect output energy; the modified version satisfies the design requirements. Our PS results were confirmed by multi-particle beam-dynamics codes that used the MWS-calculated RF fields.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO098

Export •

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