IPAC2019 - List of Authors (Aiba, M.)

Paper	Title	Page
TUPGW066	Exploring the Potential of the Swiss Light Source	1554
	M. Aiba, M. Böge, A. Citterio, M.M. Dehler, A. Lüdeke, C. Ozkan Loch, L. Stingelin, A. Streun PSI, Villigen PSI, Switzerland
	Swiss Light Source (SLS) has been on-line since 2001. Although its performance meets the specifications, it still has a potential to achieve better storage ring beam parameters. We explore two possible improvements. The first one is for the beam lifetime. There are 480 rf buckets while normally 390 bunches are stored. The gap in filing pattern (90 empty buckets) is held to suppress ion instability. After many years of operation, however, the vacuum condition is much better than that of the time when the SLS was turned on. Hence it is possible to shorten the gap. The beam lifetime can then be prolonged due to less bunch current while keeping the net beam current. The study may be also useful to predict possible filling patter in SLS2, which is the SLS upgrade planned. The second one is for the beam emittance. The nominal energy closed orbit coincides with the axes of quadrupole magnets. An off-momentum closed orbit is therefore off-centered through quadrupoles, resulting in a damping partition shift. The beam emittance can be decreased at the expense of a larger energy spread. This was successfully achieved in the ESRF booster. We study whether it is applicable to the SLS storage ring.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW066
About •	paper received ※ 13 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
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TUPGW095	Progress on a Novel 7BA Lattice for a 196-m Circumference Diffraction-Limited Soft X-Ray Storage Ring	1635
	S.C. Leemann, F. Sannibale LBNL, Berkeley, California, USA M. Aiba, A. Streun PSI, Villigen PSI, Switzerland J. Bengtsson DLS, Oxfordshire, United Kingdom L.O. Dallin CLS, Saskatoon, Saskatchewan, Canada
	Funding: Work supported by the Director of the Office of Science of the US Department of Energy under Contract No. DEAC02-05CH11231. The ALS Upgrade to a diffraction-limited soft x-ray storage ring calls for ultralow emittance in a very limited circumference. In this paper we report on progress with a lattice based on a 7BA with distributed chromatic correction. This lattice relies heavily on longitudinal gradient bends and reverse bending in order to suppress the emittance, so that, despite having only seven bends, ultralow emittance can be achieved in addition to large dynamic aperture and momentum acceptance. An initial alternate 7BA lattice has been revised to relax magnet requirements as well as further increase off-energy performance and resilience to machine imperfections. We now demonstrate ±2.5 mm dynamic aperture including errors and calculate the effect of IBS to show that this lattice achieves 6 hours Touschek lifetime (at 500 mA, including errors) and a brightness of roughly 3x10²¹ ph/s/mm²/mrad²/0.1%BW at 1 keV.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW095
About •	paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPGW107	Overview of Collective Effects in SLS 2.0	1658
	M.M. Dehler, M. Aiba, A. Citterio, L. Stingelin PSI, Villigen PSI, Switzerland
	At the end of 2017, the conceptual design for an upgrade of the Swiss Light Source was finished, promising a 40 fold smaller emittance and a corresponding increase of the spectral brightness from the current value. From the point of view of collective effects, the main changes in the new design are a reduced chamber size, fully coated with NEG, and operation at small and negative momentum compaction with low synchrotron frequency. We give an overview of the latest results for the ring. Most critical is the threshold for the longitudinal single bunch instability. Taking into account the combined effect of wake impedances and CSR, we have to rely on bunch stretching by a higher harmonic system to achieve stable operation at nominal current.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW107
About •	paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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WEPMP029	Systematic Optics Studies for the Commissioning of the AWAKE Beamline	2383
	C. Bracco, B. Goddard, I. Gorgisyan, M. Turner, F.M. Velotti, L. Verra CERN, Meyrin, Switzerland M. Aiba PSI, Villigen PSI, Switzerland
	The commissioning of the AWAKE electron beam line was successfully completed in 2018. Despite a modest length of about 15 m, this low-energy line is quite complex and several iterations were needed before finding satisfactory agreement between the model and the measurements. The work allowed to precisely predict the size and positioning of the electron beam at the merging point with the protons inside the plasma cell, where no direct measurement is possible. All the key aspects and corrections which had to be included in the model, precautions and systematic checks to apply for the correct setup of the line are presented. The sensitivity of the ~18 MeV electron beam to various perturbations, like different initial optics parameters and beam conditions, energy jitter and drifts, earth’s magnetic field etc., is described.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP029
About •	paper received ※ 10 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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WEPGW079	A Channel Access Software Platform for Beam Dynamics Applications in Scripting Languages	2661
	J.T.M. Chrin, M. Aiba, J. Snuverink PSI, Villigen PSI, Switzerland
	To facilitate the seamless integration of EPICS (Experimental Physics and Industrial Control System) into high-level applications in particle accelerators, a dedicated modern C++ Channel Access Interface (CAFE) library* provides a comprehensive and user-friendly interface to the underlying control system. Functionality is provided for synchronous and asynchronous interaction of single and composite groups of channels, coupled with an abstract layer tailored towards beam dynamics applications and complex modelling of virtual accelerators. Equivalent consumable solutions in scripting and domain-specific languages can then be accelerated by providing bindings to the relevant methods of the interface platform. This is exemplified by CAFE’s extensive MATLAB interface, incarnated through a single MATLAB executable (mex) file, and a high performance Python interface written in the Cython programming language. A number of gratifying particularities specific to these language extension modules are revealed. * http://cafe.psi.ch
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW079
About •	paper received ※ 15 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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Paper

Title

Page

Exploring the Potential of the Swiss Light Source

1554

M. Aiba, M. Böge, A. Citterio, M.M. Dehler, A. Lüdeke, C. Ozkan Loch, L. Stingelin, A. Streun
PSI, Villigen PSI, Switzerland

Swiss Light Source (SLS) has been on-line since 2001. Although its performance meets the specifications, it still has a potential to achieve better storage ring beam parameters. We explore two possible improvements. The first one is for the beam lifetime. There are 480 rf buckets while normally 390 bunches are stored. The gap in filing pattern (90 empty buckets) is held to suppress ion instability. After many years of operation, however, the vacuum condition is much better than that of the time when the SLS was turned on. Hence it is possible to shorten the gap. The beam lifetime can then be prolonged due to less bunch current while keeping the net beam current. The study may be also useful to predict possible filling patter in SLS2, which is the SLS upgrade planned. The second one is for the beam emittance. The nominal energy closed orbit coincides with the axes of quadrupole magnets. An off-momentum closed orbit is therefore off-centered through quadrupoles, resulting in a damping partition shift. The beam emittance can be decreased at the expense of a larger energy spread. This was successfully achieved in the ESRF booster. We study whether it is applicable to the SLS storage ring.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW066

About •

paper received ※ 13 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

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

TUPGW095

Progress on a Novel 7BA Lattice for a 196-m Circumference Diffraction-Limited Soft X-Ray Storage Ring

1635

S.C. Leemann, F. Sannibale
LBNL, Berkeley, California, USA
M. Aiba, A. Streun
PSI, Villigen PSI, Switzerland
J. Bengtsson
DLS, Oxfordshire, United Kingdom
L.O. Dallin
CLS, Saskatoon, Saskatchewan, Canada

Funding: Work supported by the Director of the Office of Science of the US Department of Energy under Contract No. DEAC02-05CH11231.
The ALS Upgrade to a diffraction-limited soft x-ray storage ring calls for ultralow emittance in a very limited circumference. In this paper we report on progress with a lattice based on a 7BA with distributed chromatic correction. This lattice relies heavily on longitudinal gradient bends and reverse bending in order to suppress the emittance, so that, despite having only seven bends, ultralow emittance can be achieved in addition to large dynamic aperture and momentum acceptance. An initial alternate 7BA lattice has been revised to relax magnet requirements as well as further increase off-energy performance and resilience to machine imperfections. We now demonstrate ±2.5 mm dynamic aperture including errors and calculate the effect of IBS to show that this lattice achieves 6 hours Touschek lifetime (at 500 mA, including errors) and a brightness of roughly 3x10²¹ ph/s/mm²/mrad²/0.1%BW at 1 keV.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW095

About •

paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

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

TUPGW107

Overview of Collective Effects in SLS 2.0

1658

M.M. Dehler, M. Aiba, A. Citterio, L. Stingelin
PSI, Villigen PSI, Switzerland

At the end of 2017, the conceptual design for an upgrade of the Swiss Light Source was finished, promising a 40 fold smaller emittance and a corresponding increase of the spectral brightness from the current value. From the point of view of collective effects, the main changes in the new design are a reduced chamber size, fully coated with NEG, and operation at small and negative momentum compaction with low synchrotron frequency. We give an overview of the latest results for the ring. Most critical is the threshold for the longitudinal single bunch instability. Taking into account the combined effect of wake impedances and CSR, we have to rely on bunch stretching by a higher harmonic system to achieve stable operation at nominal current.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW107

About •

paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

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

WEPMP029

Systematic Optics Studies for the Commissioning of the AWAKE Beamline

2383

C. Bracco, B. Goddard, I. Gorgisyan, M. Turner, F.M. Velotti, L. Verra
CERN, Meyrin, Switzerland
M. Aiba
PSI, Villigen PSI, Switzerland

The commissioning of the AWAKE electron beam line was successfully completed in 2018. Despite a modest length of about 15 m, this low-energy line is quite complex and several iterations were needed before finding satisfactory agreement between the model and the measurements. The work allowed to precisely predict the size and positioning of the electron beam at the merging point with the protons inside the plasma cell, where no direct measurement is possible. All the key aspects and corrections which had to be included in the model, precautions and systematic checks to apply for the correct setup of the line are presented. The sensitivity of the ~18 MeV electron beam to various perturbations, like different initial optics parameters and beam conditions, energy jitter and drifts, earth’s magnetic field etc., is described.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP029

About •

paper received ※ 10 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

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

WEPGW079

A Channel Access Software Platform for Beam Dynamics Applications in Scripting Languages

2661

J.T.M. Chrin, M. Aiba, J. Snuverink
PSI, Villigen PSI, Switzerland

To facilitate the seamless integration of EPICS (Experimental Physics and Industrial Control System) into high-level applications in particle accelerators, a dedicated modern C++ Channel Access Interface (CAFE) library* provides a comprehensive and user-friendly interface to the underlying control system. Functionality is provided for synchronous and asynchronous interaction of single and composite groups of channels, coupled with an abstract layer tailored towards beam dynamics applications and complex modelling of virtual accelerators. Equivalent consumable solutions in scripting and domain-specific languages can then be accelerated by providing bindings to the relevant methods of the interface platform. This is exemplified by CAFE’s extensive MATLAB interface, incarnated through a single MATLAB executable (mex) file, and a high performance Python interface written in the Cython programming language. A number of gratifying particularities specific to these language extension modules are revealed.
* http://cafe.psi.ch

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW079

About •

paper received ※ 15 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

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