IPAC2017 - List of Authors (Andersson, Å.)

Paper	Title	Page
WEPAB073	First Measurements of Pulse Picking by Resonant Excitation (PPRE) at the MAX IV 3 GeV Storage Ring	2750
	T. Olsson, Å. Andersson MAX IV Laboratory, Lund University, Lund, Sweden
	At synchrotron light storage rings there is demand for serving high-brilliance users requesting multibunch operation while simultaneously serving timing users who require single-bunch operation. One method to accomplish this is PPRE developed and currently in user operation at BESSY-II. In the method, the transverse emittance of one of the bunches in the bunch train is increased by an incoherent betatron excitation. Part of the light from this bunch can then be separated from the multibunch light by an aperture in the beamline, resulting in single-bunch light for the experiment. Methods such as this expand the scope of storage rings without requiring special fill patterns. This is of growing interest due to the upgrade trend towards diffraction-limited storage rings where it becomes more challenging to operate with inhomogeneous fill patterns. Measurements of PPRE were performed at the MAX IV 3 GeV storage ring utilizing the bunch-by-bunch feedback system both for excitation and as a diagnostic. Furthermore, measurements involving direct beam imaging at the diagnostics beamline allowed quantifying the effect of this excitation on the horizontal and vertical emittance.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPAB073
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WEPAB075	First Optics and Beam Dynamics Studies on the MAX IV 3 GeV Storage Ring	2756
	S.C. Leemann, Å. Andersson, M. Sjöström MAX IV Laboratory, Lund University, Lund, Sweden
	We present results from beam commissioning of the MAX IV 3 GeV storage ring as well as a summary of the beam dynamics studies that have so for been carried out. We report on injection and accumulation using a single dipole kicker, top-up injection, slow orbit feedback, restoring the linear optics to design, effects of in-vacuum undulators with closed gaps, and adjusting nonlinear optics to achieve design chromaticity correction as well as dynamic aperture sufficient for high injection efficiency and good Touschek lifetime.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPAB075
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THPAB135	Digital LLRF for MAX IV	4037
	A. Salom, F. Pérez ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain Å. Andersson, R. Lindvall, L. Malmgren, A.M. Milan, A.M. Mitrovic MAX IV Laboratory, Lund University, Lund, Sweden
	The MAX IV facility consists of a 3 GeV Storage Ring(SR), a 1.5 GeV SR, and a linear accelerator (fed by two guns) that serves as a full-energy injector to the rings, but also as a driver for the Short Pulse Facility. The RF systems of the two SRs work at 100MHz. There are 6 normal conducting capacity loaded accelerating cavities and three Landau passive cavities in the 3GeV SR. In the 1.5GeV SR there are two accelerating cavities and two Landau cavities with the same characteristics. Each of these cavities is fed by a modular 60kW SSA. In the 3 GeV SR the power will be doubled by adding a second SSA when required. A digital Low Level RF system has been developed using commercial uTCA boards, with a Virtex-6 FPGA mother board (Perseus 601X) and two double stack FMC boards with fast ADCs and DACs. The large capabilities of state-of-the-art FPGAs allowed including the control of two normal conducing cavities and two landau cavities in one single LLRF system, reducing the development costs. Other utilities like the handling of fast interlocks and post-mortem analysis were also added to this system. This paper summarizes the main capabilities and performance of this DLLRF.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB135
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Paper

Title

Page

First Measurements of Pulse Picking by Resonant Excitation (PPRE) at the MAX IV 3 GeV Storage Ring

2750

T. Olsson, Å. Andersson
MAX IV Laboratory, Lund University, Lund, Sweden

At synchrotron light storage rings there is demand for serving high-brilliance users requesting multibunch operation while simultaneously serving timing users who require single-bunch operation. One method to accomplish this is PPRE developed and currently in user operation at BESSY-II. In the method, the transverse emittance of one of the bunches in the bunch train is increased by an incoherent betatron excitation. Part of the light from this bunch can then be separated from the multibunch light by an aperture in the beamline, resulting in single-bunch light for the experiment. Methods such as this expand the scope of storage rings without requiring special fill patterns. This is of growing interest due to the upgrade trend towards diffraction-limited storage rings where it becomes more challenging to operate with inhomogeneous fill patterns. Measurements of PPRE were performed at the MAX IV 3 GeV storage ring utilizing the bunch-by-bunch feedback system both for excitation and as a diagnostic. Furthermore, measurements involving direct beam imaging at the diagnostics beamline allowed quantifying the effect of this excitation on the horizontal and vertical emittance.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPAB073

Export •

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

WEPAB075

First Optics and Beam Dynamics Studies on the MAX IV 3 GeV Storage Ring

2756

S.C. Leemann, Å. Andersson, M. Sjöström
MAX IV Laboratory, Lund University, Lund, Sweden

We present results from beam commissioning of the MAX IV 3 GeV storage ring as well as a summary of the beam dynamics studies that have so for been carried out. We report on injection and accumulation using a single dipole kicker, top-up injection, slow orbit feedback, restoring the linear optics to design, effects of in-vacuum undulators with closed gaps, and adjusting nonlinear optics to achieve design chromaticity correction as well as dynamic aperture sufficient for high injection efficiency and good Touschek lifetime.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPAB075

Export •

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

THPAB135

Digital LLRF for MAX IV

4037

A. Salom, F. Pérez
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
Å. Andersson, R. Lindvall, L. Malmgren, A.M. Milan, A.M. Mitrovic
MAX IV Laboratory, Lund University, Lund, Sweden

The MAX IV facility consists of a 3 GeV Storage Ring(SR), a 1.5 GeV SR, and a linear accelerator (fed by two guns) that serves as a full-energy injector to the rings, but also as a driver for the Short Pulse Facility. The RF systems of the two SRs work at 100MHz. There are 6 normal conducting capacity loaded accelerating cavities and three Landau passive cavities in the 3GeV SR. In the 1.5GeV SR there are two accelerating cavities and two Landau cavities with the same characteristics. Each of these cavities is fed by a modular 60kW SSA. In the 3 GeV SR the power will be doubled by adding a second SSA when required. A digital Low Level RF system has been developed using commercial uTCA boards, with a Virtex-6 FPGA mother board (Perseus 601X) and two double stack FMC boards with fast ADCs and DACs. The large capabilities of state-of-the-art FPGAs allowed including the control of two normal conducing cavities and two landau cavities in one single LLRF system, reducing the development costs. Other utilities like the handling of fast interlocks and post-mortem analysis were also added to this system. This paper summarizes the main capabilities and performance of this DLLRF.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB135

Export •

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