SRF2017 - List of Keywords (impedance)

Paper	Title	Other Keywords	Page
MOPB001	Concepts and Design for Beamline HOM Dampers for eRHIC	ion, HOM, cavity, linac	39
	P. Kolb, Y. Gao, D. Holmes, K.S. Smith, W. Xu BNL, Upton, Long Island, New York, USA Y. Gao PKU, Beijing, People's Republic of China
	Funding: Work supported by LDRD program of Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE. In the design of eRHIC at BNL, HOM power plays a major role for the SRF installation. Depending on the final accelerator design and choice of cavity, up to 100kW of HOM power is estimated to be generated, presenting a big challenge for the HOM damping concept. Due to this high amount of HOM power, all current concepts for eRHIC would use room temperature beam line absorbers equipped with silicone-carbide dielectrics to absorb HOM power. Concepts, designs and simulations for these beam line absorbers will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-MOPB001
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MOPB002	eRHIC Crab Cavity Choice for Ring-ring Design	ion, cavity, luminosity, electron	43
	Q. Wu, I. Ben-Zvi, Y. Hao, S. Verdú-Andrés, B. P. Xiao BNL, Upton, Long Island, New York, USA
	Funding: This work was supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE. The future electron ion collider eRHIC adopts large crossing angle (22 mrad) to allow fast separation of two beams in the ring-ring scheme. Crab cavities are required to recover the luminosity from geometric losses. Initial calculation shows that the frequency of the cavities for the ion beam is no more than 336MHz. In this paper, we discuss the crab cavity related lattice parameters for both ion and electron beams in ring-ring design, the frequency choice, and the cavity design considerations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-MOPB002
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MOPB004	Design of a RF Quadrupole Resonator for Landau Damping in HL-LHC	ion, cavity, quadrupole, damping	51
	K. Papke, A. Grudiev CERN, Geneva, Switzerland
	The design and optimization of a quadrupole resonator for transverse Landau damping in the High Luminosity Large Hadron Collider (HL-LHC) is presented. Two different cavity types are considered whose shape is determined by quadrupolar strength, surface peak fields, and beam coupling impedance. The lower order and higher order mode (LOM and HOM) spectra of the optimized cavities are investigated and different approaches for their damping are proposed. Along an example, the required RF power and optimal external quality factor for the input coupler is derived.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-MOPB004
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MOPB017	Multiphysics Simulations of the Wide Opened Waveguide Crab-cavity	ion, cavity, HOM, dipole	90
	K. Papke, A. Amorim Carvalho, A. Grudiev, C. Zanoni CERN, Geneva, Switzerland
	In the frame of a FCC study a first prototype of a compact superconducting crab-cavity, using Nb-on-Cu-coating technique is being manufactured and investigated. The design, which is based on the ridged waveguide resonator, is subjected to multipacting and pressure sensitivity simulations. First results of theses simulations are presented and compared to those of other SRF cavities. Furthermore, several aspects related to the design of the fundamental mode coupler and HOM dampers are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-MOPB017
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MOPB066	Development of 81.25 MHz 20 kW SSPA for RAON Accelerator	ion, rfq, cavity, power-supply	210
	C.O. Choi, H. Jang, H.C. Jung, D.Y. Lee, K.T. Son IBS, Daejeon, Republic of Korea
	A heavy ion accelerator, RAON is under development in Daejeon, Korea by Rare Isotope Science Project (RISP). In this accelerator, 81.25 MHz Radio Frequency Quadrupole (RFQ) will be used for the acceleration of various ions from several tens of keV/u to about half MeV/u. For this system two 80 kW RF power sources are planned and RISP will develop them with a solid state power amplifier (SSPA) architecture. As a first step, a 20 kW SSPA was developed and its performance was tested. In this presentation the current status of developed SSPA and its test results will be presented
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-MOPB066
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MOPB068	Development of 4-way 81.25 MHz 20 kW High Power Combiner Using Parallel Plate Structure	ion, simulation, cavity, rfq	213
	K.T. Son, C.O. Choi, H. Jang, H.C. Jung, D.Y. Lee IBS, Daejeon, Republic of Korea
	The recent development of semiconductor technology has proved that solid-state RF amplifier is a quite effective alternative high power RF source for numerous accelerator applications. To develop a high power SSPA system, high power combiner is required to combine the RF power from a lot of solid-state RF module. The parallel plate RF power combiner, which is designed to combine various high power modules, is developed for RAON(Rare the rare isotope accelerator complex for on-line experiment). In this presentation, the status of developed 81.25 MHz 20 kW power combiner will be described.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-MOPB068
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MOPB079	HOM Coupler Alterations for the LHC DQW Crab Cavity	ion, cavity, HOM, simulation	249
	J.A. Mitchell Lancaster University, Lancaster, United Kingdom G. Burt, N.C. Shipman Cockcroft Institute, Lancaster University, Lancaster, United Kingdom R. Calaga CERN, Geneva, Switzerland S. Verdú-Andrés, Q. Wu, B. P. Xiao BNL, Upton, Long Island, New York, USA
	As part of the High Luminosity Large Hadron Collider (HL-LHC) project, 16 crab cavities are to be installed in the LHC in 2025. The two crab cavity designs are the Double Quarter Wave (DQW) and Radio Frequency Dipole (RFD). Preliminary beam tests in the Super Proton Synchrotron (SPS) are planned for both cavity types, with the DQW scheduled for testing in 2018. In reference to to Higher Order Mode (HOM) damping, the DQW has three identical on-cell HOM couplers. These HOM couplers provide a band-stop response at the frequency of the fundamental mode and act as a transmission path for the cavity HOMs. For the SPS cavity design, several geometric constraints exist. These give rise to dimensional limitations which in-turn impose limitations on the RF performance of the HOM couplers. As such, for the LHC assembly, the HOM coupler design is re-visited to take into account the relaxed geometric limitations, hence allowing the feasibility of an increased RF performance to be investigated. In addition to the RF performance, several geometric alterations were incorporated to ease manufacturing processes, tolerances and costs.
	Poster MOPB079 [2.038 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-MOPB079
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TUPB004	HOM damping with an enlarged beam tube for HEPS 166.6 MHz SC cavities	HOM, ion, cavity, damping	389
	H.X. Hao, Z.Q. Li, F. Meng, P. Zhang, X.Y. Zhang IHEP, Beijing, People's Republic of China
	The 166.6 MHz superconducting cavities have been proposed for the High Energy Photon Source (HEPS) storage ring, which is initiated by the Institute of High Energy Physics in Beijing. Their higher order modes (HOMs) have to be damped sufficiently in order to limit coupled-bunch instabilities and parasitic mode losses. In order to keep the beam stable, the impedance budget and the HOM damping requirement are given. As one HOM damping option, an enlarged beam tube allows HOMs to propagate and subsequently be absorbed by downstream HOM dampers installed on the inner surface of the beam tube. And the conventional coaxial HOM coupler, which will be mounted on the big beam tube, is planned to extract the HOM power below the cut-off frequency of the beam pipe.
	Poster TUPB004 [1.132 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-TUPB004
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

MOPB001

Concepts and Design for Beamline HOM Dampers for eRHIC

ion, HOM, cavity, linac

39

P. Kolb, Y. Gao, D. Holmes, K.S. Smith, W. Xu
BNL, Upton, Long Island, New York, USA
Y. Gao
PKU, Beijing, People's Republic of China

Funding: Work supported by LDRD program of Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE.
In the design of eRHIC at BNL, HOM power plays a major role for the SRF installation. Depending on the final accelerator design and choice of cavity, up to 100kW of HOM power is estimated to be generated, presenting a big challenge for the HOM damping concept. Due to this high amount of HOM power, all current concepts for eRHIC would use room temperature beam line absorbers equipped with silicone-carbide dielectrics to absorb HOM power. Concepts, designs and simulations for these beam line absorbers will be presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-MOPB001

Export •

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

MOPB002

eRHIC Crab Cavity Choice for Ring-ring Design

ion, cavity, luminosity, electron

43

Q. Wu, I. Ben-Zvi, Y. Hao, S. Verdú-Andrés, B. P. Xiao
BNL, Upton, Long Island, New York, USA

Funding: This work was supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE.
The future electron ion collider eRHIC adopts large crossing angle (22 mrad) to allow fast separation of two beams in the ring-ring scheme. Crab cavities are required to recover the luminosity from geometric losses. Initial calculation shows that the frequency of the cavities for the ion beam is no more than 336MHz. In this paper, we discuss the crab cavity related lattice parameters for both ion and electron beams in ring-ring design, the frequency choice, and the cavity design considerations.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-MOPB002

Export •

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

MOPB004

Design of a RF Quadrupole Resonator for Landau Damping in HL-LHC

ion, cavity, quadrupole, damping

51

K. Papke, A. Grudiev
CERN, Geneva, Switzerland

The design and optimization of a quadrupole resonator for transverse Landau damping in the High Luminosity Large Hadron Collider (HL-LHC) is presented. Two different cavity types are considered whose shape is determined by quadrupolar strength, surface peak fields, and beam coupling impedance. The lower order and higher order mode (LOM and HOM) spectra of the optimized cavities are investigated and different approaches for their damping are proposed. Along an example, the required RF power and optimal external quality factor for the input coupler is derived.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-MOPB004

Export •

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

MOPB017

Multiphysics Simulations of the Wide Opened Waveguide Crab-cavity

ion, cavity, HOM, dipole

90

K. Papke, A. Amorim Carvalho, A. Grudiev, C. Zanoni
CERN, Geneva, Switzerland

In the frame of a FCC study a first prototype of a compact superconducting crab-cavity, using Nb-on-Cu-coating technique is being manufactured and investigated. The design, which is based on the ridged waveguide resonator, is subjected to multipacting and pressure sensitivity simulations. First results of theses simulations are presented and compared to those of other SRF cavities. Furthermore, several aspects related to the design of the fundamental mode coupler and HOM dampers are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-MOPB017

Export •

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

MOPB066

Development of 81.25 MHz 20 kW SSPA for RAON Accelerator

ion, rfq, cavity, power-supply

210

C.O. Choi, H. Jang, H.C. Jung, D.Y. Lee, K.T. Son
IBS, Daejeon, Republic of Korea

A heavy ion accelerator, RAON is under development in Daejeon, Korea by Rare Isotope Science Project (RISP). In this accelerator, 81.25 MHz Radio Frequency Quadrupole (RFQ) will be used for the acceleration of various ions from several tens of keV/u to about half MeV/u. For this system two 80 kW RF power sources are planned and RISP will develop them with a solid state power amplifier (SSPA) architecture. As a first step, a 20 kW SSPA was developed and its performance was tested. In this presentation the current status of developed SSPA and its test results will be presented

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-MOPB066

Export •

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

MOPB068

Development of 4-way 81.25 MHz 20 kW High Power Combiner Using Parallel Plate Structure

ion, simulation, cavity, rfq

213

K.T. Son, C.O. Choi, H. Jang, H.C. Jung, D.Y. Lee
IBS, Daejeon, Republic of Korea

The recent development of semiconductor technology has proved that solid-state RF amplifier is a quite effective alternative high power RF source for numerous accelerator applications. To develop a high power SSPA system, high power combiner is required to combine the RF power from a lot of solid-state RF module. The parallel plate RF power combiner, which is designed to combine various high power modules, is developed for RAON(Rare the rare isotope accelerator complex for on-line experiment). In this presentation, the status of developed 81.25 MHz 20 kW power combiner will be described.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-MOPB068

Export •

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

MOPB079

HOM Coupler Alterations for the LHC DQW Crab Cavity

ion, cavity, HOM, simulation

249

J.A. Mitchell
Lancaster University, Lancaster, United Kingdom
G. Burt, N.C. Shipman
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
R. Calaga
CERN, Geneva, Switzerland
S. Verdú-Andrés, Q. Wu, B. P. Xiao
BNL, Upton, Long Island, New York, USA

As part of the High Luminosity Large Hadron Collider (HL-LHC) project, 16 crab cavities are to be installed in the LHC in 2025. The two crab cavity designs are the Double Quarter Wave (DQW) and Radio Frequency Dipole (RFD). Preliminary beam tests in the Super Proton Synchrotron (SPS) are planned for both cavity types, with the DQW scheduled for testing in 2018. In reference to to Higher Order Mode (HOM) damping, the DQW has three identical on-cell HOM couplers. These HOM couplers provide a band-stop response at the frequency of the fundamental mode and act as a transmission path for the cavity HOMs. For the SPS cavity design, several geometric constraints exist. These give rise to dimensional limitations which in-turn impose limitations on the RF performance of the HOM couplers. As such, for the LHC assembly, the HOM coupler design is re-visited to take into account the relaxed geometric limitations, hence allowing the feasibility of an increased RF performance to be investigated. In addition to the RF performance, several geometric alterations were incorporated to ease manufacturing processes, tolerances and costs.

Poster MOPB079 [2.038 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-MOPB079

Export •

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

TUPB004

HOM damping with an enlarged beam tube for HEPS 166.6 MHz SC cavities

HOM, ion, cavity, damping

389

H.X. Hao, Z.Q. Li, F. Meng, P. Zhang, X.Y. Zhang
IHEP, Beijing, People's Republic of China

The 166.6 MHz superconducting cavities have been proposed for the High Energy Photon Source (HEPS) storage ring, which is initiated by the Institute of High Energy Physics in Beijing. Their higher order modes (HOMs) have to be damped sufficiently in order to limit coupled-bunch instabilities and parasitic mode losses. In order to keep the beam stable, the impedance budget and the HOM damping requirement are given. As one HOM damping option, an enlarged beam tube allows HOMs to propagate and subsequently be absorbed by downstream HOM dampers installed on the inner surface of the beam tube. And the conventional coaxial HOM coupler, which will be mounted on the big beam tube, is planned to extract the HOM power below the cut-off frequency of the beam pipe.

Poster TUPB004 [1.132 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-TUPB004

Export •

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