ERL2019 - List of Keywords (simulation)

Paper	Title	Other Keywords	Page
WEPNEC10	Investigation on the Ion Clearing of Multi-Purpose Electrodes of BERLinPro	electron, brightness, linac, emittance	80
	G. Pöplau COMPAEC e.G., Rostock, Germany A. Meseck KPH, Mainz, Germany A. Meseck HZB, Berlin, Germany
	High-brightness electron beams provided by modern accelerators require several measures to preserve their high quality and to avoid instabilities. The mitigation of the impact of residual ions is one of these measures. It is particularly important if high bunch charges in combination with high repetition rates are aimed for. This is because ions can be trapped in the strong negative electrical potential of the electron beam causing emittance blow-up, increased beam halo and longitudinal and transverse instabilities. One ion-clearing strategy is the installation of clearing electrodes. Of particular interest in this context is the performance of multi-purpose electrodes, which are designed such that they allow for a simultaneous ion-clearing and beam-position monitoring. Such electrodes will be installed in the BERLinPro facility. In this contribution, we present numerical studies of the performance of multi-purpose clearing-electrodes planned for BERLinPro, i.e. we investigate the behavior of ions generated by electron bunches while passing through the field of the electrodes. Hereby, several ion species and configurations of electrodes are considered.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ERL2019-WEPNEC10
About •	paper received ※ 11 October 2019 paper accepted ※ 06 November 2019 issue date ※ 24 June 2020
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WEPNEC22	Beam Impedance Study on a Harmonic Kicker for the CCR of JLEIC	impedance, cavity, HOM, kicker	116
	G.-T. Park, J. Guo, F. Marhauser, R.A. Rimmer, H. Wang, S. Wang JLab, Newport News, Virginia, USA
	Funding: Work supported by Jefferson Science Associates, LLC under U.S DOE Contract No. DE-AC05-06OR23177 In this report, we present the development of a fast harmonic kicker, a normal conducting deflecting cavity that kicks electron bunches from ERL ring to circulator cooler ring (CCR) in Jefferson Lab Electron Ion Collider (JLEIC). This cavity utilizes 5 harmonic modes to generate a sharp kick to the electron bunch at high frequency of 86.6MHz, which is injection frequency into the CCR. The beam dynamics study and RF design of the hardware was reported in [1],[2]. In this report we present further progress including impedance by higher order mode (HOM) study and mechanical design for fabrication. [1] G. Park, et. al TUPAL068, Proc. of IPAC 2018, Apr 2018, Vancouver, BC Canada [2] G. Park, et. al, Proc. of IPAC2019, May 2019, Melbourne, Australia
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ERL2019-WEPNEC22
About •	paper received ※ 30 September 2019 paper accepted ※ 04 November 2019 issue date ※ 24 June 2020
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THCOWBS03	System Identification Procedures for Resonance Frequency Control of SC Cavities	controls, operation, cryomodule, linac	129
	S. Orth, H. Klingbeil TEMF, TU Darmstadt, Darmstadt, Germany
	Funding: Work supported by Deutsche Forschungsgemeinschaft (DFG): GRK 2128 ’AccelencE’ Energy Recovery Linacs promise superior beam quality: sharper and more intense. To reach these goals, resonance frequency control of the superconducting RF cavities is an important part. In this work, system identification procedures conducted at components of the S-DALINAC (Institute for Nuclear Physics, TU Darmstadt, Germany) are shown. This includes investigations of the piezo tuner’s effect on, e.g., the phase of the accelerating field when a periodic disturbance is applied. The results are compared to simulations of the modelled system and the impact of the applied controller is discussed.
	Slides THCOWBS03 [0.593 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ERL2019-THCOWBS03
About •	paper received ※ 17 September 2019 paper accepted ※ 01 November 2019 issue date ※ 24 June 2020
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THCOWBS06	Beam Breakup Limit Estimations and Higher Order Mode Characterisation for MESA	cavity, HOM, dipole, cryomodule	134
	C.P. Stoll, F. Hug KPH, Mainz, Germany
	Funding: Work supported by the German Research Foundation (DFG) under the Cluster of Excellence "PRISMA+" EXC 2118/2019, through RTG2128 Accelence and by ARIES. MESA is a two pass energy recovery linac (ERL) currently under construction at the Johannes Gutenberg-University in Mainz. MESA uses two 1.3 GHz TESLA type cavities with 12.5 MV/m of accelerating gradient in a modified ELBE type cryomodule in c.w. operation. One potential limit to maximum beam current in ERLs is the transverse beam breakup (BBU) instability induced by dipole HOMs. These modes can be excited by bunches passing through the cavities off axis. Following bunches are then deflected by the HOMs, which results in even larger offsets for recirculated bunches. This feedback can even lead to beam loss. To measure the quality factors and frequencies for the dressed as well as undressed cavities improves the validity of any current limit estimation done.
	Slides THCOWBS06 [3.256 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ERL2019-THCOWBS06
About •	paper received ※ 18 September 2019 paper accepted ※ 04 November 2019 issue date ※ 24 June 2020
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

WEPNEC10

Investigation on the Ion Clearing of Multi-Purpose Electrodes of BERLinPro

electron, brightness, linac, emittance

80

G. Pöplau
COMPAEC e.G., Rostock, Germany
A. Meseck
KPH, Mainz, Germany
A. Meseck
HZB, Berlin, Germany

High-brightness electron beams provided by modern accelerators require several measures to preserve their high quality and to avoid instabilities. The mitigation of the impact of residual ions is one of these measures. It is particularly important if high bunch charges in combination with high repetition rates are aimed for. This is because ions can be trapped in the strong negative electrical potential of the electron beam causing emittance blow-up, increased beam halo and longitudinal and transverse instabilities. One ion-clearing strategy is the installation of clearing electrodes. Of particular interest in this context is the performance of multi-purpose electrodes, which are designed such that they allow for a simultaneous ion-clearing and beam-position monitoring. Such electrodes will be installed in the BERLinPro facility. In this contribution, we present numerical studies of the performance of multi-purpose clearing-electrodes planned for BERLinPro, i.e. we investigate the behavior of ions generated by electron bunches while passing through the field of the electrodes. Hereby, several ion species and configurations of electrodes are considered.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ERL2019-WEPNEC10

About •

paper received ※ 11 October 2019 paper accepted ※ 06 November 2019 issue date ※ 24 June 2020

Export •

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

WEPNEC22

Beam Impedance Study on a Harmonic Kicker for the CCR of JLEIC

impedance, cavity, HOM, kicker

116

G.-T. Park, J. Guo, F. Marhauser, R.A. Rimmer, H. Wang, S. Wang
JLab, Newport News, Virginia, USA

Funding: Work supported by Jefferson Science Associates, LLC under U.S DOE Contract No. DE-AC05-06OR23177
In this report, we present the development of a fast harmonic kicker, a normal conducting deflecting cavity that kicks electron bunches from ERL ring to circulator cooler ring (CCR) in Jefferson Lab Electron Ion Collider (JLEIC). This cavity utilizes 5 harmonic modes to generate a sharp kick to the electron bunch at high frequency of 86.6MHz, which is injection frequency into the CCR. The beam dynamics study and RF design of the hardware was reported in [1],[2]. In this report we present further progress including impedance by higher order mode (HOM) study and mechanical design for fabrication.
[1] G. Park, et. al TUPAL068, Proc. of IPAC 2018, Apr 2018, Vancouver, BC Canada
[2] G. Park, et. al, Proc. of IPAC2019, May 2019, Melbourne, Australia

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ERL2019-WEPNEC22

About •

paper received ※ 30 September 2019 paper accepted ※ 04 November 2019 issue date ※ 24 June 2020

Export •

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

THCOWBS03

System Identification Procedures for Resonance Frequency Control of SC Cavities

controls, operation, cryomodule, linac

129

S. Orth, H. Klingbeil
TEMF, TU Darmstadt, Darmstadt, Germany

Funding: Work supported by Deutsche Forschungsgemeinschaft (DFG): GRK 2128 ’AccelencE’
Energy Recovery Linacs promise superior beam quality: sharper and more intense. To reach these goals, resonance frequency control of the superconducting RF cavities is an important part. In this work, system identification procedures conducted at components of the S-DALINAC (Institute for Nuclear Physics, TU Darmstadt, Germany) are shown. This includes investigations of the piezo tuner’s effect on, e.g., the phase of the accelerating field when a periodic disturbance is applied. The results are compared to simulations of the modelled system and the impact of the applied controller is discussed.

Slides THCOWBS03 [0.593 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ERL2019-THCOWBS03

About •

paper received ※ 17 September 2019 paper accepted ※ 01 November 2019 issue date ※ 24 June 2020

Export •

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

THCOWBS06

Beam Breakup Limit Estimations and Higher Order Mode Characterisation for MESA

cavity, HOM, dipole, cryomodule

134

C.P. Stoll, F. Hug
KPH, Mainz, Germany

Funding: Work supported by the German Research Foundation (DFG) under the Cluster of Excellence "PRISMA+" EXC 2118/2019, through RTG2128 Accelence and by ARIES.
MESA is a two pass energy recovery linac (ERL) currently under construction at the Johannes Gutenberg-University in Mainz. MESA uses two 1.3 GHz TESLA type cavities with 12.5 MV/m of accelerating gradient in a modified ELBE type cryomodule in c.w. operation. One potential limit to maximum beam current in ERLs is the transverse beam breakup (BBU) instability induced by dipole HOMs. These modes can be excited by bunches passing through the cavities off axis. Following bunches are then deflected by the HOMs, which results in even larger offsets for recirculated bunches. This feedback can even lead to beam loss. To measure the quality factors and frequencies for the dressed as well as undressed cavities improves the validity of any current limit estimation done.

Slides THCOWBS06 [3.256 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ERL2019-THCOWBS06

About •

paper received ※ 18 September 2019 paper accepted ※ 04 November 2019 issue date ※ 24 June 2020

Export •

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