HB2016 - List of Keywords (closed-orbit)

Paper	Title	Other Keywords	Page
MOPR036	Spin Tracking of Polarized Protons in the Main Injector at Fermilab	polarization, lattice, resonance, proton	173
	M. Xiao Fermilab, Batavia, Illinois, USA C. Aldred, W. Lorenzon Michigan University, Ann Arbor, Michigan, USA
	The Main Injector (MI) at Fermilab currently produces high-intensity beams of protons at energies of 120 GeV for a variety of physics experiments. Acceleration of polarized protons in the MI would provide opportunities for a rich spin physics program at Fermilab. To achieve polarized proton beams in the Fermilab accelerator com-plex, shown in Fig.1.1, detailed spin tracking simulations with realistic parameters based on the existing facility are required. This report presents studies at the MI using a single 4-twist Siberian snake to determine the depolariz-ing spin resonances for the relevant synchrotrons. Results will be presented first for a perfect MI lattice, followed by a lattice that includes the real MI imperfections, such as the measured magnet field errors and quadrupole misa-lignments. The tolerances of each of these factors in maintaining polarization in the Main Injector will be discussed.
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MOPL024	Study of Magnets Sorting of the CSNS/RCS Dipoles and Quadrupoles*	dipole, quadrupole, injection, lattice	247
	Y.W. An, H.F. Ji, Y. Li, S. Wang, S.Y. Xu IHEP, Beijing, People's Republic of China J. Peng CSNS, Guangdong Province, People's Republic of China
	Funding: Work supported by National Natural Science Foundation of China (11405189)* The Rapid Cycling Synchrotron plays an important role in the China Spallation Neutron Source. RCS accumulates and accelerates the proton beams from 80MeV to 1.6GeV for striking the target with the repetition rate of 25Hz. RCS demands low uncontrolled loss for hands on maintenance, and one needs a tight tolerance on magnet field accuracy. Magnet sorting can be done to minimize linear effects of beam dynamics. Using closed-orbit distortion (COD) and beta-beating independently as the merit function, and considering maintaining the symmetry of the lattice, a code based on traversal algorithm is developed to get the dipoles and quadrupoles sorting for CSNS/RCS. The comparison of beam distribution, collimation efficiency and beam loss are also investigated according to beam injection and beam accelerating.
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TUAM7X01	Intensity Effects in the Formation of Stable Islands in Phase Space During the Multi-Turn Extraction Process at the CERN PS	space-charge, simulation, vacuum, extraction	283
	S. Machida STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom S.S. Gilardoni, M. Giovannozzi, S. Hirlaender, A. Huschauer CERN, Geneva, Switzerland C.R. Prior STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	The CERN PS utilises a multi-turn extraction (MTE) scheme to stretch the beam pulse length to optimise the filling process of the SPS. MTE is a novel technique to split a beam in transverse phase space into nonlinear stable islands. The recent experimental results indicate that the positions of the islands depend on the total beam intensity. Particle simulations have been performed to understand the detailed mechanism of the intensity dependence. The analysis carried out so far suggests space charge effects through image charges and image currents on the vacuum chamber and the magnets’ iron cores dominate the observed behaviour. In this talk, the latest analysis with realistic modelling of the beam environment is discussed and it is shown how this further improves the understanding of intensity effects in MTE.
	Slides TUAM7X01 [1.682 MB]
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THPM6X01	Space Charge Effects in FFAG	space-charge, lattice, betatron, emittance	499
	M. Haj Tahar, F. Méot 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. Understanding space charge effects in FFAG is crucial in order to assess their potential for high power applications. This paper shows that, to carry out parametric studies of these effects in FFAG, the average field index of the focusing and defocusing magnets are the natural parametrization. Using several classes of particle distribution functions, we investigate the effects of space charge forces on the non-linear beam dynamics of FFAG and provide stability diagrams for an FFAG-like lattice. The method developed in this study is mainly applicable to systems with slowly varying parameters, i.e slow acceleration.
	Slides THPM6X01 [2.171 MB]
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Paper

Title

Other Keywords

Page

MOPR036

Spin Tracking of Polarized Protons in the Main Injector at Fermilab

polarization, lattice, resonance, proton

173

M. Xiao
Fermilab, Batavia, Illinois, USA
C. Aldred, W. Lorenzon
Michigan University, Ann Arbor, Michigan, USA

The Main Injector (MI) at Fermilab currently produces high-intensity beams of protons at energies of 120 GeV for a variety of physics experiments. Acceleration of polarized protons in the MI would provide opportunities for a rich spin physics program at Fermilab. To achieve polarized proton beams in the Fermilab accelerator com-plex, shown in Fig.1.1, detailed spin tracking simulations with realistic parameters based on the existing facility are required. This report presents studies at the MI using a single 4-twist Siberian snake to determine the depolariz-ing spin resonances for the relevant synchrotrons. Results will be presented first for a perfect MI lattice, followed by a lattice that includes the real MI imperfections, such as the measured magnet field errors and quadrupole misa-lignments. The tolerances of each of these factors in maintaining polarization in the Main Injector will be discussed.

Export •

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

MOPL024

Study of Magnets Sorting of the CSNS/RCS Dipoles and Quadrupoles*

dipole, quadrupole, injection, lattice

247

Y.W. An, H.F. Ji, Y. Li, S. Wang, S.Y. Xu
IHEP, Beijing, People's Republic of China
J. Peng
CSNS, Guangdong Province, People's Republic of China

Funding: Work supported by National Natural Science Foundation of China (11405189)*
The Rapid Cycling Synchrotron plays an important role in the China Spallation Neutron Source. RCS accumulates and accelerates the proton beams from 80MeV to 1.6GeV for striking the target with the repetition rate of 25Hz. RCS demands low uncontrolled loss for hands on maintenance, and one needs a tight tolerance on magnet field accuracy. Magnet sorting can be done to minimize linear effects of beam dynamics. Using closed-orbit distortion (COD) and beta-beating independently as the merit function, and considering maintaining the symmetry of the lattice, a code based on traversal algorithm is developed to get the dipoles and quadrupoles sorting for CSNS/RCS. The comparison of beam distribution, collimation efficiency and beam loss are also investigated according to beam injection and beam accelerating.

Export •

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

TUAM7X01

Intensity Effects in the Formation of Stable Islands in Phase Space During the Multi-Turn Extraction Process at the CERN PS

space-charge, simulation, vacuum, extraction

283

S. Machida
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
S.S. Gilardoni, M. Giovannozzi, S. Hirlaender, A. Huschauer
CERN, Geneva, Switzerland
C.R. Prior
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

The CERN PS utilises a multi-turn extraction (MTE) scheme to stretch the beam pulse length to optimise the filling process of the SPS. MTE is a novel technique to split a beam in transverse phase space into nonlinear stable islands. The recent experimental results indicate that the positions of the islands depend on the total beam intensity. Particle simulations have been performed to understand the detailed mechanism of the intensity dependence. The analysis carried out so far suggests space charge effects through image charges and image currents on the vacuum chamber and the magnets’ iron cores dominate the observed behaviour. In this talk, the latest analysis with realistic modelling of the beam environment is discussed and it is shown how this further improves the understanding of intensity effects in MTE.

Slides TUAM7X01 [1.682 MB]

Export •

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

THPM6X01

Space Charge Effects in FFAG

space-charge, lattice, betatron, emittance

499

M. Haj Tahar, F. Méot
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.
Understanding space charge effects in FFAG is crucial in order to assess their potential for high power applications. This paper shows that, to carry out parametric studies of these effects in FFAG, the average field index of the focusing and defocusing magnets are the natural parametrization. Using several classes of particle distribution functions, we investigate the effects of space charge forces on the non-linear beam dynamics of FFAG and provide stability diagrams for an FFAG-like lattice. The method developed in this study is mainly applicable to systems with slowly varying parameters, i.e slow acceleration.

Slides THPM6X01 [2.171 MB]

Export •

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