IPAC2015 - List of Authors (Tavares, P.F.)

Paper	Title	Page
MOPWA011	The Damping of Transverse Coherent Instabilities by Harmonic Cavities	102
	F.J. Cullinan, R. Nagaoka SOLEIL, Gif-sur-Yvette, France G. Skripka, P.F. Tavares MAX-lab, Lund, Sweden
	At nonzero chromaticity, the threshold current due to transverse coupled bunch instabilities in an electron storage ring is defined by intrabunch head-tail motion of higher than zeroth order. Multibunch tracking simulations predict that this threshold can be increased to several times its original value through the introduction of bunch lengthening harmonic cavities. One previously suggested explanation is the narrower spectra of the elongated bunches but reliable estimates for the threshold currents are not obtainable for anything other than rigid beam motion since the usual Sacherer formulism is not directly applicable to beams in a non-harmonic potential. A new scheme has been developed in which the decay time of a higher than zeroth order transverse head-tail mode may be estimated by taking into account the synchrotron tune spread generated by the harmonic cavity potential. This scheme is presented along with the results of numerical simulations performed in order to confirm the analytical predictions and justify the assumptions made. The extension of the scheme to more complex scenarios is also discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWA011
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WEPMN062	MAX IV 3 GeV Storage Ring Magnet Block Production Series Measurement Results	3069
	M.A.G. Johansson, L.-J. Lindgren, M. Sjöström, P.F. Tavares MAX-lab, Lund, Sweden
	The magnet design of the MAX IV 3 GeV storage ring replaces the conventional support girder + discrete magnets scheme of previous third-generation synchrotron radiation light sources with a compact (Ø25 mm aperture) integrated design having several consecutive magnet elements precision-machined out of a common solid iron block, with mechanical tolerances of ±0.02 mm over the 2.3–3.4 m block length. The production series of 140 integrated magnet block units, which was totally outsourced to industry, was completed mid-2014, with mechanical/magnetic QA conforming to specifications. This article presents mechanical and magnetic field measurement results of the full production series.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN062
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

The Damping of Transverse Coherent Instabilities by Harmonic Cavities

102

F.J. Cullinan, R. Nagaoka
SOLEIL, Gif-sur-Yvette, France
G. Skripka, P.F. Tavares
MAX-lab, Lund, Sweden

At nonzero chromaticity, the threshold current due to transverse coupled bunch instabilities in an electron storage ring is defined by intrabunch head-tail motion of higher than zeroth order. Multibunch tracking simulations predict that this threshold can be increased to several times its original value through the introduction of bunch lengthening harmonic cavities. One previously suggested explanation is the narrower spectra of the elongated bunches but reliable estimates for the threshold currents are not obtainable for anything other than rigid beam motion since the usual Sacherer formulism is not directly applicable to beams in a non-harmonic potential. A new scheme has been developed in which the decay time of a higher than zeroth order transverse head-tail mode may be estimated by taking into account the synchrotron tune spread generated by the harmonic cavity potential. This scheme is presented along with the results of numerical simulations performed in order to confirm the analytical predictions and justify the assumptions made. The extension of the scheme to more complex scenarios is also discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWA011

Export •

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

WEPMN062

MAX IV 3 GeV Storage Ring Magnet Block Production Series Measurement Results

3069

M.A.G. Johansson, L.-J. Lindgren, M. Sjöström, P.F. Tavares
MAX-lab, Lund, Sweden

The magnet design of the MAX IV 3 GeV storage ring replaces the conventional support girder + discrete magnets scheme of previous third-generation synchrotron radiation light sources with a compact (Ø25 mm aperture) integrated design having several consecutive magnet elements precision-machined out of a common solid iron block, with mechanical tolerances of ±0.02 mm over the 2.3–3.4 m block length. The production series of 140 integrated magnet block units, which was totally outsourced to industry, was completed mid-2014, with mechanical/magnetic QA conforming to specifications. This article presents mechanical and magnetic field measurement results of the full production series.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN062

Export •

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