IPAC2014 - List of Authors (Tsoupas, N.)

Paper	Title	Page
TUPRO077	AGS Snake Stories	1220
	F. Méot, Y. Dutheil, R.C. Gupta, H. Huang, N. Tsoupas BNL, Upton, Long Island, New York, USA J. Takano J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. This contribution re-visits fields, particle motion, and spin precession in the AGS helical polarization snakes. The work was undertaken in preparation of orbit and spin modeling for future polarized proton and helion runs at RHIC. The investigations include re-computation of 3-D OPERA field maps of the helical snakes and particle and spin tracking. There is a series of sub-products of this study, amongst others, the appropriate settings of the AGS cold snake when changing its strength, cold snake settings for polarized helion programs, non-linear coupling in the AGS, the transport of the stable polarization axis from the AGS to RHIC injection kickers, and in addition, a series of high accuracy 3-D field maps have been produced, in view of long-term tracking in the AGS for beam and polarization transmission studies.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO077
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WEPRO070	Overcoming the Horizontal Depolarizing Resonance in the Brookhaven AGS	2112
	H. Huang, L. Ahrens, M. Bai, M. Blaskiewicz, K.A. Brown, R. Connolly, Y. Dutheil, W. Fischer, C.J. Gardner, J.W. Glenn, T. Hayes, F. Méot, A. Poblaguev, V.H. Ranjbar, T. Roser, V. Schoefer, K.S. Smith, S. Tepikian, N. Tsoupas, K. Yip, A. Zelenski, K. Zeno, S.Y. Zhang BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Imperfection and vertical intrinsic depolarizing resonances have been overcome by the two partial Siberian snakes in the AGS. The relatively weak but numerous horizontal resonances are the main source of polarization loss in the AGS. A pair of horizontal quads have been used to overcome these weak resonances. This technique needs very accurate jump timing. Fast roll-over magnet cycle has been used and it improves the polarization transmission efficiency near extraction when acceleration usually is slowing down. Emittance preservation is also important to mitigate polarization loss. Recent experimental results including jump quad timing and emittance preservation are presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO070
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WEPRO071	Optics Setup in the AGS and AGS Booster for Polarized Helion Beam	2115
	H. Huang, L. Ahrens, J.G. Alessi, M. Bai, E.N. Beebe, M. Blaskiewicz, K.A. Brown, Y. Dutheil, W. Fischer, C.J. Gardner, J.W. Glenn, T. Hayes, F. Méot, A. Poblaguev, V.H. Ranjbar, T. Roser, V. Schoefer, K.S. Smith, S. Tepikian, N. Tsoupas, K. Yip, A. Zelenski, K. Zeno BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Future RHIC physics program calls for polarized He3 beam. The He3 beam from the new EBIS source has a relative low rigidity which requires delicate control of injection and RF setup in the Booster. The strong depolarization resonance strength in both AGS and AGS Booster requires careful consideration of beam energy range and optics setup. Recently, the He3 beam was accelerated to 11GeV/n in the AGS. The near term goal fo 3*10¹⁰ at RHIC requires several RF bunch merges in both AGS and the Booster. The beam test results are presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO071
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THPRO088	Optimization of the pp AGS Zgoubi Model in the Low Energy Range	3089
	Y. Dutheil, H. Huang, F. Méot, N. Tsoupas BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. At low energy the AGS lattice is strongly deformed by the two strong helical snakes, required to preserve the polarization. In addition to the complex, highly non-linear field featured by the two snakes, multiple non-linear coupling resonance lines are crossed by the beam in this region. Hence, the use of realistic models for the Siberian snakes is critical for the simulation of the early part of the AGS acceleration cycle. The AGS Zgoubi model uses direct tracking through OPERA field maps of the two snakes. While many processes may be obnoxious to both beam and spin dynamics in this region, it is critical to use a realistic model of the AGS at low energy. This paper presents the current model used and some of the challenges recently faced. We will also compare experimental beam dynamics results to those predicted by the Zgoubi model.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO088
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Paper

Title

Page

AGS Snake Stories

1220

F. Méot, Y. Dutheil, R.C. Gupta, H. Huang, N. Tsoupas
BNL, Upton, Long Island, New York, USA
J. Takano
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
This contribution re-visits fields, particle motion, and spin precession in the AGS helical polarization snakes. The work was undertaken in preparation of orbit and spin modeling for future polarized proton and helion runs at RHIC. The investigations include re-computation of 3-D OPERA field maps of the helical snakes and particle and spin tracking. There is a series of sub-products of this study, amongst others, the appropriate settings of the AGS cold snake when changing its strength, cold snake settings for polarized helion programs, non-linear coupling in the AGS, the transport of the stable polarization axis from the AGS to RHIC injection kickers, and in addition, a series of high accuracy 3-D field maps have been produced, in view of long-term tracking in the AGS for beam and polarization transmission studies.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO077

Export •

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

WEPRO070

Overcoming the Horizontal Depolarizing Resonance in the Brookhaven AGS

2112

H. Huang, L. Ahrens, M. Bai, M. Blaskiewicz, K.A. Brown, R. Connolly, Y. Dutheil, W. Fischer, C.J. Gardner, J.W. Glenn, T. Hayes, F. Méot, A. Poblaguev, V.H. Ranjbar, T. Roser, V. Schoefer, K.S. Smith, S. Tepikian, N. Tsoupas, K. Yip, A. Zelenski, K. Zeno, S.Y. Zhang
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Imperfection and vertical intrinsic depolarizing resonances have been overcome by the two partial Siberian snakes in the AGS. The relatively weak but numerous horizontal resonances are the main source of polarization loss in the AGS. A pair of horizontal quads have been used to overcome these weak resonances. This technique needs very accurate jump timing. Fast roll-over magnet cycle has been used and it improves the polarization transmission efficiency near extraction when acceleration usually is slowing down. Emittance preservation is also important to mitigate polarization loss. Recent experimental results including jump quad timing and emittance preservation are presented in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO070

Export •

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

WEPRO071

Optics Setup in the AGS and AGS Booster for Polarized Helion Beam

2115

H. Huang, L. Ahrens, J.G. Alessi, M. Bai, E.N. Beebe, M. Blaskiewicz, K.A. Brown, Y. Dutheil, W. Fischer, C.J. Gardner, J.W. Glenn, T. Hayes, F. Méot, A. Poblaguev, V.H. Ranjbar, T. Roser, V. Schoefer, K.S. Smith, S. Tepikian, N. Tsoupas, K. Yip, A. Zelenski, K. Zeno
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Future RHIC physics program calls for polarized He3 beam. The He3 beam from the new EBIS source has a relative low rigidity which requires delicate control of injection and RF setup in the Booster. The strong depolarization resonance strength in both AGS and AGS Booster requires careful consideration of beam energy range and optics setup. Recently, the He3 beam was accelerated to 11GeV/n in the AGS. The near term goal fo 3*10¹⁰ at RHIC requires several RF bunch merges in both AGS and the Booster. The beam test results are presented in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO071

Export •

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

THPRO088

Optimization of the pp AGS Zgoubi Model in the Low Energy Range

3089

Y. Dutheil, H. Huang, F. Méot, N. Tsoupas
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
At low energy the AGS lattice is strongly deformed by the two strong helical snakes, required to preserve the polarization. In addition to the complex, highly non-linear field featured by the two snakes, multiple non-linear coupling resonance lines are crossed by the beam in this region. Hence, the use of realistic models for the Siberian snakes is critical for the simulation of the early part of the AGS acceleration cycle. The AGS Zgoubi model uses direct tracking through OPERA field maps of the two snakes. While many processes may be obnoxious to both beam and spin dynamics in this region, it is critical to use a realistic model of the AGS at low energy. This paper presents the current model used and some of the challenges recently faced. We will also compare experimental beam dynamics results to those predicted by the Zgoubi model.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO088

Export •

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