IPAC2021 - List of Authors (Meseck, A.)

Paper	Title	Page
MOPAB126	BESSY III & MLS II - Status of the Development of the New Photon Science Facility in Berlin	451
	P. Goslawski, M. Abo-Bakr, F. Andreas, M. Arlandoo, J. Bengtsson, V. Dürr, K. Holldack, J.-G. Hwang, A. Jankowiak, B.C. Kuske, J. Li, A.N. Matveenko, T. Mertens, A. Meseck, E.C.M. Rial, M. Ries, M.K. Sauerborn, A. Schälicke, M. Scheer, P. Schnizer, L. Shi, J. Viefhaus HZB, Berlin, Germany J. Lüning UPMC, Paris, France
	HZB operates and develops two synchrotron radiation sources at Berlin Adlershof. The larger one, BESSY II with an energy of 1.7 GeV and 240 m circumference is optimized for soft-X rays and in operation since 1999. The smaller one is the MLS (Metrology Light Source), owned by the Physikalische Technische Bundesanstalt (PTB) - Germany’s National Metrology Institute. It is designed to fulfill the special metrology needs of the PTB with an energy of 0.6 GeV and 48 m circumference, covering the spectral range from THz and IR to EUV/VUV. In 2020 a discussion process has been started to define the requirements for successors of BESSY II and MLS and to study the possibilities integrate them into a new photon science facility in Berlin Adlershof. Here, we give a status report and present a first envisaged parameter space to both machines (see also MOPAB262, MOPAB220, MOPAB048, MOPAB242).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB126
About •	paper received ※ 18 May 2021 paper accepted ※ 24 June 2021 issue date ※ 18 August 2021
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TUPAB217	Effect of Undulators on Transverse Resonant Island Orbits	1927
	E.C.M. Rial, J. Bahrdt, P. Goslawski, A. Meseck, M. Ries, M. Scheer HZB, Berlin, Germany
	For one week in October 2020, BESSY II offered a Two Orbit mode to users for the first time. In this Two Orbit mode, the existence of transverse resonant island buckets* are exploited to store a second beam in the storage ring as an ’island orbit’, away from the primary beam axis. This mode was offered with free range of motion of the 12 out of vacuum undulators installed at the BESSY II ring. Diagnostics of the island orbit were limited to a single camera monitoring bending magnet radiation from a single dipole. A significant motion of the island orbit was observed on this diagnostic and correlated with undulator motion. This observation is reported, and simulations presented to demonstrate how this motion could arise. Correction schemes are suggested and discussed. Two Orbit - a report on the first scheduled week of TRIBs user operation at BESSY II, M. Ries et al, these proceedings *Proc. IPAC 2016, Busan, S Korea, paper THPMR017, p. 3427
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB217
About •	paper received ※ 19 May 2021 paper accepted ※ 21 June 2021 issue date ※ 22 August 2021
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WEPAB133	First Numerical Wakefield Studies of New In-Vacuum Cryogenic and APPLE II Undulators for BESSY II	2925
	M. Huck, J. Bahrdt, A. Meseck HZB, Berlin, Germany A. Meseck KPH, Mainz, Germany
	While the new in-vacuum cryogenic undulator is in its last commissioning stages, a worldwide new in-vacuum APPLE II undulator is being designed and constructed for BESSY II storage ring. Besides the challenging mechanical design of these small-gap and short-period undulators, challenges arise due to interaction with the electron beam. Therefore, detailed studies of this interaction is required to minimize the adverse effects on beam dynamics and the device itself. For this purpose, the wakefield effects have been computed numerically for critical parts of these devices i.e. the RF-shields, flexible tapers and taper sections. A brief overview of simulation results and discussions are presented in this paper.
	Poster WEPAB133 [0.795 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB133
About •	paper received ※ 19 May 2021 paper accepted ※ 23 July 2021 issue date ※ 23 August 2021
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WEPAB134	Experimental Studies of the In-Vacuum-Cryogenic Undulator Effect on Beam Instabilities at BESSY II	2929
	M. Huck, J. Bahrdt, A. Meseck, G. Rehm, M. Ries, A. Schälicke HZB, Berlin, Germany
	A new in-vacuum cryogenic permanent magnet undulator (CPMU17) has been installed in summer 2018 in the BESSY II storage ring at HZB. Such a small gap in-vacuum undulator device increases the impedance of the storage ring and can contribute to the instabilities that adversely affect the beam quality and the device itself. To identify and explore the effects of CPMU17 on the instabilities at BESSY II, grow-damp and drive-damp experiments have been conducted using the installed bunch-by-bunch feedback system. In this paper, the first results of the mode and gap analysis of these studies with a brief overview of other impedance studies will be presented.
	Poster WEPAB134 [1.079 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB134
About •	paper received ※ 17 May 2021 paper accepted ※ 02 July 2021 issue date ※ 23 August 2021
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THPAB057	Goubau-Line Set Up for Bench Testing Impedance of In-Vacuum Undulator Components	3883
	P.I. Volz, S. Grimmer, M. Huck, A. Meseck HZB, Berlin, Germany A. Meseck KPH, Mainz, Germany
	The worldwide first in-vacuum elliptical undulator, IVUE32, is being developed at Helmholtz Zentrum Berlin. The 2.5 m long device with a period length of 3.2 cm and a minimum gap of about 7 mm is to be installed in the BESSY II storage ring. It will deliver soft X-radiation to several beamlines. The proximity of the undulator structure to the electron beam makes the device susceptible to wakefield effects which can influence beam stability. A complete understanding of its impedance characteristics is required prior to installation and operation, as unforeseen heating of components could have catastrophic consequences. Since its complex structure makes numerical calculations, such as CST simulations, at high frequency very resource intensive, bench testing the device may proof invaluable. A Goubau-line is a single wire transmission line for high frequency surface waves with a transverse electric field resembling that of a charged particle beam out to a certain radial distance. This can be used to measure the impedance of vacuum chamber components. A concept optimized for bench testing IVUE32-components will be discussed and progress towards the test bench set up will be shown.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB057
About •	paper received ※ 19 May 2021 paper accepted ※ 23 July 2021 issue date ※ 21 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPAB217	A Storage Ring for MESA	719
	C.P. Stoll, A. Meseck KPH, Mainz, Germany B. Ledroit HIM, Mainz, Germany
	The Mainz Energy-recovering Superconducting Accelerator (MESA) is an Energy Recovery Linac (ERL) facility under construction at the Johannes Gutenberg-University in Mainz. It provides the opportunity for precision physics experiments with a 1 mA c.w. electron beam in its initial phase. In this phase experiments with unpolarised, high density 10¹⁹ atoms cm² gas jet targets are foreseen at the Mainz Gas Internal Target Experiment (MAGIX). To allow experiments with thin polarised gas targets with sufficiently high interaction rates in a later phase, the beam current has to be increased to up to 100 mA, which would pose significant challenges to the existing ERL machine. Thus, it is proposed here to use MESA in pulsed operation with a repetition rate of several kHz to fill a storage ring, providing a quasi c.w. beam current to a thin gas target. For this purpose, the existing optics need to be extended and adapted, a suitable injection and extraction scheme is necessary and beam target interaction must be investigated. First considerations on these topics are presented here.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB217
About •	paper received ※ 18 May 2021 paper accepted ※ 08 June 2021 issue date ※ 21 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPAB062	Investigation of the Thomson Scattering Influence on Electron Beam Parameters in an Energy-Recovering Linear Accelerator on the Example of MESA	2732
	C.L. Lorey, K. Aulenbacher, A. Meseck KPH, Mainz, Germany
	Funding: funded by DFG through GRK2128 ACCELENCE At the Johannes Gutenberg University (JGU) in Mainz, the Mainz Energy-recovering Superconducting Accelerator (MESA) is currently under construction. It is designed to deliver electron beams of up to 155 MeV. As it can be operated in an energy-recovery (ER) mode thus allowing for high repetition rate, it is a promising candidate for a high flux Thomson scattering based gamma source. This paper will provide a status update on the study of the impact of Thomson scattering on electron beam parameters and the underlying mechanics. Further, the implementation into a simulation code will be discussed.
	Poster WEPAB062 [1.307 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB062
About •	paper received ※ 19 May 2021 paper accepted ※ 12 July 2021 issue date ※ 02 September 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

BESSY III & MLS II - Status of the Development of the New Photon Science Facility in Berlin

451

P. Goslawski, M. Abo-Bakr, F. Andreas, M. Arlandoo, J. Bengtsson, V. Dürr, K. Holldack, J.-G. Hwang, A. Jankowiak, B.C. Kuske, J. Li, A.N. Matveenko, T. Mertens, A. Meseck, E.C.M. Rial, M. Ries, M.K. Sauerborn, A. Schälicke, M. Scheer, P. Schnizer, L. Shi, J. Viefhaus
HZB, Berlin, Germany
J. Lüning
UPMC, Paris, France

HZB operates and develops two synchrotron radiation sources at Berlin Adlershof. The larger one, BESSY II with an energy of 1.7 GeV and 240 m circumference is optimized for soft-X rays and in operation since 1999. The smaller one is the MLS (Metrology Light Source), owned by the Physikalische Technische Bundesanstalt (PTB) - Germany’s National Metrology Institute. It is designed to fulfill the special metrology needs of the PTB with an energy of 0.6 GeV and 48 m circumference, covering the spectral range from THz and IR to EUV/VUV. In 2020 a discussion process has been started to define the requirements for successors of BESSY II and MLS and to study the possibilities integrate them into a new photon science facility in Berlin Adlershof. Here, we give a status report and present a first envisaged parameter space to both machines (see also MOPAB262, MOPAB220, MOPAB048, MOPAB242).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB126

About •

paper received ※ 18 May 2021 paper accepted ※ 24 June 2021 issue date ※ 18 August 2021

Export •

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

TUPAB217

Effect of Undulators on Transverse Resonant Island Orbits

1927

E.C.M. Rial, J. Bahrdt, P. Goslawski, A. Meseck, M. Ries, M. Scheer
HZB, Berlin, Germany

For one week in October 2020, BESSY II offered a Two Orbit mode to users for the first time*. In this Two Orbit mode, the existence of transverse resonant island buckets** are exploited to store a second beam in the storage ring as an ’island orbit’, away from the primary beam axis. This mode was offered with free range of motion of the 12 out of vacuum undulators installed at the BESSY II ring. Diagnostics of the island orbit were limited to a single camera monitoring bending magnet radiation from a single dipole. A significant motion of the island orbit was observed on this diagnostic and correlated with undulator motion. This observation is reported, and simulations presented to demonstrate how this motion could arise. Correction schemes are suggested and discussed.
*Two Orbit - a report on the first scheduled week of TRIBs user operation at BESSY II, M. Ries et al, these proceedings
**Proc. IPAC 2016, Busan, S Korea, paper THPMR017, p. 3427

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB217

About •

paper received ※ 19 May 2021 paper accepted ※ 21 June 2021 issue date ※ 22 August 2021

Export •

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

WEPAB133

First Numerical Wakefield Studies of New In-Vacuum Cryogenic and APPLE II Undulators for BESSY II

2925

M. Huck, J. Bahrdt, A. Meseck
HZB, Berlin, Germany
A. Meseck
KPH, Mainz, Germany

While the new in-vacuum cryogenic undulator is in its last commissioning stages, a worldwide new in-vacuum APPLE II undulator is being designed and constructed for BESSY II storage ring. Besides the challenging mechanical design of these small-gap and short-period undulators, challenges arise due to interaction with the electron beam. Therefore, detailed studies of this interaction is required to minimize the adverse effects on beam dynamics and the device itself. For this purpose, the wakefield effects have been computed numerically for critical parts of these devices i.e. the RF-shields, flexible tapers and taper sections. A brief overview of simulation results and discussions are presented in this paper.

Poster WEPAB133 [0.795 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB133

About •

paper received ※ 19 May 2021 paper accepted ※ 23 July 2021 issue date ※ 23 August 2021

Export •

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

WEPAB134

Experimental Studies of the In-Vacuum-Cryogenic Undulator Effect on Beam Instabilities at BESSY II

2929

M. Huck, J. Bahrdt, A. Meseck, G. Rehm, M. Ries, A. Schälicke
HZB, Berlin, Germany

A new in-vacuum cryogenic permanent magnet undulator (CPMU17) has been installed in summer 2018 in the BESSY II storage ring at HZB. Such a small gap in-vacuum undulator device increases the impedance of the storage ring and can contribute to the instabilities that adversely affect the beam quality and the device itself. To identify and explore the effects of CPMU17 on the instabilities at BESSY II, grow-damp and drive-damp experiments have been conducted using the installed bunch-by-bunch feedback system. In this paper, the first results of the mode and gap analysis of these studies with a brief overview of other impedance studies will be presented.

Poster WEPAB134 [1.079 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB134

About •

paper received ※ 17 May 2021 paper accepted ※ 02 July 2021 issue date ※ 23 August 2021

Export •

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

THPAB057

Goubau-Line Set Up for Bench Testing Impedance of In-Vacuum Undulator Components

3883

P.I. Volz, S. Grimmer, M. Huck, A. Meseck
HZB, Berlin, Germany
A. Meseck
KPH, Mainz, Germany

The worldwide first in-vacuum elliptical undulator, IVUE32, is being developed at Helmholtz Zentrum Berlin. The 2.5 m long device with a period length of 3.2 cm and a minimum gap of about 7 mm is to be installed in the BESSY II storage ring. It will deliver soft X-radiation to several beamlines. The proximity of the undulator structure to the electron beam makes the device susceptible to wakefield effects which can influence beam stability. A complete understanding of its impedance characteristics is required prior to installation and operation, as unforeseen heating of components could have catastrophic consequences. Since its complex structure makes numerical calculations, such as CST simulations, at high frequency very resource intensive, bench testing the device may proof invaluable. A Goubau-line is a single wire transmission line for high frequency surface waves with a transverse electric field resembling that of a charged particle beam out to a certain radial distance. This can be used to measure the impedance of vacuum chamber components. A concept optimized for bench testing IVUE32-components will be discussed and progress towards the test bench set up will be shown.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB057

About •

paper received ※ 19 May 2021 paper accepted ※ 23 July 2021 issue date ※ 21 August 2021

Export •

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

MOPAB217

A Storage Ring for MESA

719

C.P. Stoll, A. Meseck
KPH, Mainz, Germany
B. Ledroit
HIM, Mainz, Germany

The Mainz Energy-recovering Superconducting Accelerator (MESA) is an Energy Recovery Linac (ERL) facility under construction at the Johannes Gutenberg-University in Mainz. It provides the opportunity for precision physics experiments with a 1 mA c.w. electron beam in its initial phase. In this phase experiments with unpolarised, high density 10¹⁹ atoms cm² gas jet targets are foreseen at the Mainz Gas Internal Target Experiment (MAGIX). To allow experiments with thin polarised gas targets with sufficiently high interaction rates in a later phase, the beam current has to be increased to up to 100 mA, which would pose significant challenges to the existing ERL machine. Thus, it is proposed here to use MESA in pulsed operation with a repetition rate of several kHz to fill a storage ring, providing a quasi c.w. beam current to a thin gas target. For this purpose, the existing optics need to be extended and adapted, a suitable injection and extraction scheme is necessary and beam target interaction must be investigated. First considerations on these topics are presented here.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB217

About •

paper received ※ 18 May 2021 paper accepted ※ 08 June 2021 issue date ※ 21 August 2021

Export •

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

WEPAB062

Investigation of the Thomson Scattering Influence on Electron Beam Parameters in an Energy-Recovering Linear Accelerator on the Example of MESA

2732

C.L. Lorey, K. Aulenbacher, A. Meseck
KPH, Mainz, Germany

Funding: funded by DFG through GRK2128 ACCELENCE
At the Johannes Gutenberg University (JGU) in Mainz, the Mainz Energy-recovering Superconducting Accelerator (MESA) is currently under construction. It is designed to deliver electron beams of up to 155 MeV. As it can be operated in an energy-recovery (ER) mode thus allowing for high repetition rate, it is a promising candidate for a high flux Thomson scattering based gamma source. This paper will provide a status update on the study of the impact of Thomson scattering on electron beam parameters and the underlying mechanics. Further, the implementation into a simulation code will be discussed.

Poster WEPAB062 [1.307 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB062

About •

paper received ※ 19 May 2021 paper accepted ※ 12 July 2021 issue date ※ 02 September 2021

Export •

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