IPAC2018 - List of Keywords (brightness)

Paper	Title	Other Keywords	Page
TUPAF047	Systematic Studies of Transverse Emittance Measurements Along the CERN PS Booster Cycle	emittance, scattering, betatron, proton	806
	A. Santamaría García, S.C.P. Albright, H. Bartosik, J.A. Briz Monago, G.P. Di Giovanni, V. Forte, B. Mikulec, F. Roncarolo, V. Vlachoudis CERN, Geneva, Switzerland
	The CERN Proton Synchrotron Booster (PSB) will need to deliver 2 times the current brightness to the Large Hadron Collider (LHC) after the LHC Injectors Upgrade (LIU) to meet the High-Luminosity-LHC beam requirements. Beam intensity and transverse emittance are the key parameters to increase brightness, the latter being more difficult to manipulate. It is, therefore, crucial to monitor not only the emittance evolution between the different injectors but also along each acceleration cycle. To this end, detailed emittance measurements were carried out for the four rings of the PSB at various times in the cycle with different beam types. A thorough analysis of systematic error sources was conducted including multiple Coulomb scattering happening during profile measurements with wire scanners, where experimental and analytical treatments of the emittance blow-up were compared to FLUKA simulations. In order to properly account for the dispersive contribution, the full momentum spread profile was considered using a deconvolution method. We conclude with an assessment of this first comprehensive emittance evolution measurement along the PSB cycle.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF047
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TUPMF056	Brightness Dependence Investigation and Optimizaiton for the Heps	lattice, emittance, photon, undulator	1390
	Y. Jiao, M. Li, X.Y. Li IHEP, Beijing, People's Republic of China
	The High Energy Photon Source (HEPS) is an ultralow-emittance, kilometer-scale storage ring light source to be built in China. To maximize the photon spectral brightness, one of the most important performance parameters of the light source, we investigated the dependence of brightness on different parameters, such as the natural emittance, coupling, beta functions of the undulator section, and length of the undulator section. Based on this study, we optimized the HEPS lattice by using brightness as an optimizing objective.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF056
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WEPAF063	RF Manipulations for Special LHC-Type Beams in the CERN PS	extraction, emittance, flattop, cavity	1971
	H. Damerau, S. Hancock, A. Lasheen, D. Perrelet CERN, Geneva, Switzerland
	Beams with special longitudinal characteristics for the Large Hadron Collider (LHC) have been produced in the Proton Synchrotron (PS) and CERN. The flexibility of its RF systems consisting of in total 25 RF cavities at frequencies from 400 kHz to 200 MHz allows a variety of longitudinal beam manipulations. In particular the main RF system is split into three independent groups tunable from 2.8 MHz to 10 MHz. It is used to merge, split and change the spacing between bunches by applying different voltage and phase programs to the three groups of cavities at different harmonic numbers simultaneously. The batch compression, merging and splitting (BCMS) process has been operationally used for LHC fillings since 2016. To mitigate issues with long bunch trains in the LHC in 2017, short gaps of four bunch positions have been introduced between mini-batches of eight bunches (8b4e). A higher brightness version resulting in four mini-batches per PS extraction has been delivered for luminosity production in the LHC. This paper summarizes the operational experience and indicates possible future RF manipulation schemes.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF063
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THPAF087	Multi-Objective Optimization of an SRF Photoinjector with Booster Section for High Brightness Beam Performance	booster, cavity, emittance, gun	3193
	E. Panofski, A. Jankowiak, T. Kamps, A. Neumann HZB, Berlin, Germany
	Several future accelerator projects, light sources and user experiments require high brightness electron beams. SRF photoinjectors operating in continuous-wave (cw) mode hold the potential to serve as an electron source generating beams of high average brightness and short bunch lengths. Different operation and design parameters of the SRF photoinjector impact the beam dynamics and thus the beam brightness. A universal multi-objective optimization program based on a genetic algorithm was developed to extract optimum gun parameter settings from Pareto-optimum solutions. After getting the first optimum results, the photoinjector is supplemented with a booster section downstream. The new optimization results are presented. Further, the optimization program is applied to evaluate the impact of the field flatness of the gun cavity on the high brightness performance.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF087
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THPAK014	Analytical Estimation of the Beam Ion Instability in HEPS	simulation, operation, damping, electron	3231
	N. Wang, Z. Duan, S.K. Tian, H.S. Xu IHEP, Beijing, People's Republic of China
	The High Energy Photon Source (HEPS) is a new designed photon source at beam energy of 6 GeV, with natural beam emittance less than 100pm. Due to the small transverse beam size, beam ion instability is one of the potential issues for HEPS. The growth time of the instability is estimated analytically for different operation scenarios. The results show considerably good agreement with the wake strong simulations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK014
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THPAK085	3D Space Charge in Bmad	space-charge, simulation, software, lattice	3428
	C.E. Mayes SLAC, Menlo Park, California, USA R.D. Ryne LBNL, Berkeley, California, USA D. Sagan Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	We present a parallel fast Fourier transform based 3D space charge software library based on integrated Green functions. The library is open-source, and has been structured to easily be used by existing beam dynamics codes. We demonstrate this by incorporating it with the Bmad toolkit for charged particle simulation, and compare with analytical formulas and well-established space charge codes.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK085
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THPAK097	Ion Optic Design of the Microprobe System at Sichuan University	target, proton, focusing, quadrupole	3460
	Z. Li, Z. An, J.F. Han, G.Q. Zheng SCU, Chengdu, People's Republic of China
	Funding: Supported by the National Natural Science Foundation of China (11375122, 11511140277) At the end of 2016, the first beam was extracted from the 3.0 MV Tandetron accelerator system at Sichuan University, China. The accelerator is imported from the HVEE as a multi-purpose research platform. For one of the main applications, the system will be connected to a micro-beamline to achieve submicron resolution, so the accelerator is designed with energy stability as high as 0.01%. The measured brightness for 3 MeV proton beam is 5.06 pA/um2mrad2MeV and the energy stability is reached the goal of design. The ion optic design of the microprobe beam line will be presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK097
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THPAL009	A TM01 Mode Launcher With Quadrupole Field Components Cancellation for High Brightness Applications	network, GUI, quadrupole, gun	3631
	G. Castorina INFN-Roma1, Rome, Italy A.D. Cahill, J.B. Rosenzweig UCLA, Los Angeles, California, USA F. Cardelli, G. Franzini, A. Marcelli, B. Spataro INFN/LNF, Frascati (Roma), Italy L. Celona, S. Gammino, G. Torrisi INFN/LNS, Catania, Italy V.A. Dolgashev SLAC, Menlo Park, California, USA L. Ficcadenti Rome University La Sapienza, Roma, Italy M. Migliorati, A. Mostacci, L. Palumbo Sapienza University of Rome, Rome, Italy G. Sorbello University of Catania, Catania, Italy
	The R&D of high gradient radiofrequency (RF) devices is aimed to develop innovative accelerating structures based on new manufacturing techniques and materials in order to construct devices operating with the highest accelerating gradient. Recent studies have shown a large increase in the maximum sustained RF surface electric fields in copper structures operating at cryogenic temperatures. These novel approaches allow significant performance improvements of RF photoinjectors. Indeed the operation at high surface fields results in considerable increase of electron beam brilliance. This increased brilliance requires high field quality in the RF photoinjector and specifically in its power coupler. In this work we present a novel power coupler for the RF photoinjector. The coupler is a compact X-band TM01 mode launcher with a fourfold symmetry which minimized both the dipole and the quadrupole RF components.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL009
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THPMK118	GaN Thin Film Photocathodes for High Brightness Electron Beams	cathode, electron, target, experiment	4594
	M. Vogel, X. Jiang, M. Schumacher University Siegen, Siegen, Germany
	Funding: This work was supported by the German Federal Ministry of Education and Research under grant 05K16PS1 "HOPE II: Hochbrillante photoinduzierte Hochfrequenz-Elektronenquellen". Gallium nitride (GaN) is one promising candidate as photocathode material showing high quantum efficiencies which is one of the requirements for high brightness electron beams. In addition to reported quantum efficiencies of up to 70%, GaN needs to satisfy the demands for long lifetime, low dark current and low thermal emittance. In this contribution, the ongoing activities of the synthesis by means of reactive rf magnetron sputtering and characterization of GaN is presented. The latter is done by standard materials science methods and in-situ measurements of the quantum efficiency in combination with lifetime and dark current measurements to asses and optimize the photocathode's performance. Along with the project's details, first experimental results of GaN thin films synthesized utilizing a GaAs source are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK118
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

TUPAF047

Systematic Studies of Transverse Emittance Measurements Along the CERN PS Booster Cycle

emittance, scattering, betatron, proton

806

A. Santamaría García, S.C.P. Albright, H. Bartosik, J.A. Briz Monago, G.P. Di Giovanni, V. Forte, B. Mikulec, F. Roncarolo, V. Vlachoudis
CERN, Geneva, Switzerland

The CERN Proton Synchrotron Booster (PSB) will need to deliver 2 times the current brightness to the Large Hadron Collider (LHC) after the LHC Injectors Upgrade (LIU) to meet the High-Luminosity-LHC beam requirements. Beam intensity and transverse emittance are the key parameters to increase brightness, the latter being more difficult to manipulate. It is, therefore, crucial to monitor not only the emittance evolution between the different injectors but also along each acceleration cycle. To this end, detailed emittance measurements were carried out for the four rings of the PSB at various times in the cycle with different beam types. A thorough analysis of systematic error sources was conducted including multiple Coulomb scattering happening during profile measurements with wire scanners, where experimental and analytical treatments of the emittance blow-up were compared to FLUKA simulations. In order to properly account for the dispersive contribution, the full momentum spread profile was considered using a deconvolution method. We conclude with an assessment of this first comprehensive emittance evolution measurement along the PSB cycle.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF047

Export •

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

TUPMF056

Brightness Dependence Investigation and Optimizaiton for the Heps

lattice, emittance, photon, undulator

1390

Y. Jiao, M. Li, X.Y. Li
IHEP, Beijing, People's Republic of China

The High Energy Photon Source (HEPS) is an ultralow-emittance, kilometer-scale storage ring light source to be built in China. To maximize the photon spectral brightness, one of the most important performance parameters of the light source, we investigated the dependence of brightness on different parameters, such as the natural emittance, coupling, beta functions of the undulator section, and length of the undulator section. Based on this study, we optimized the HEPS lattice by using brightness as an optimizing objective.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF056

Export •

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

WEPAF063

RF Manipulations for Special LHC-Type Beams in the CERN PS

extraction, emittance, flattop, cavity

1971

H. Damerau, S. Hancock, A. Lasheen, D. Perrelet
CERN, Geneva, Switzerland

Beams with special longitudinal characteristics for the Large Hadron Collider (LHC) have been produced in the Proton Synchrotron (PS) and CERN. The flexibility of its RF systems consisting of in total 25 RF cavities at frequencies from 400 kHz to 200 MHz allows a variety of longitudinal beam manipulations. In particular the main RF system is split into three independent groups tunable from 2.8 MHz to 10 MHz. It is used to merge, split and change the spacing between bunches by applying different voltage and phase programs to the three groups of cavities at different harmonic numbers simultaneously. The batch compression, merging and splitting (BCMS) process has been operationally used for LHC fillings since 2016. To mitigate issues with long bunch trains in the LHC in 2017, short gaps of four bunch positions have been introduced between mini-batches of eight bunches (8b4e). A higher brightness version resulting in four mini-batches per PS extraction has been delivered for luminosity production in the LHC. This paper summarizes the operational experience and indicates possible future RF manipulation schemes.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF063

Export •

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

THPAF087

Multi-Objective Optimization of an SRF Photoinjector with Booster Section for High Brightness Beam Performance

booster, cavity, emittance, gun

3193

E. Panofski, A. Jankowiak, T. Kamps, A. Neumann
HZB, Berlin, Germany

Several future accelerator projects, light sources and user experiments require high brightness electron beams. SRF photoinjectors operating in continuous-wave (cw) mode hold the potential to serve as an electron source generating beams of high average brightness and short bunch lengths. Different operation and design parameters of the SRF photoinjector impact the beam dynamics and thus the beam brightness. A universal multi-objective optimization program based on a genetic algorithm was developed to extract optimum gun parameter settings from Pareto-optimum solutions. After getting the first optimum results, the photoinjector is supplemented with a booster section downstream. The new optimization results are presented. Further, the optimization program is applied to evaluate the impact of the field flatness of the gun cavity on the high brightness performance.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF087

Export •

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

THPAK014

Analytical Estimation of the Beam Ion Instability in HEPS

simulation, operation, damping, electron

3231

N. Wang, Z. Duan, S.K. Tian, H.S. Xu
IHEP, Beijing, People's Republic of China

The High Energy Photon Source (HEPS) is a new designed photon source at beam energy of 6 GeV, with natural beam emittance less than 100pm. Due to the small transverse beam size, beam ion instability is one of the potential issues for HEPS. The growth time of the instability is estimated analytically for different operation scenarios. The results show considerably good agreement with the wake strong simulations.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK014

Export •

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

THPAK085

3D Space Charge in Bmad

space-charge, simulation, software, lattice

3428

C.E. Mayes
SLAC, Menlo Park, California, USA
R.D. Ryne
LBNL, Berkeley, California, USA
D. Sagan
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

We present a parallel fast Fourier transform based 3D space charge software library based on integrated Green functions. The library is open-source, and has been structured to easily be used by existing beam dynamics codes. We demonstrate this by incorporating it with the Bmad toolkit for charged particle simulation, and compare with analytical formulas and well-established space charge codes.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK085

Export •

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

THPAK097

Ion Optic Design of the Microprobe System at Sichuan University

target, proton, focusing, quadrupole

3460

Z. Li, Z. An, J.F. Han, G.Q. Zheng
SCU, Chengdu, People's Republic of China

Funding: Supported by the National Natural Science Foundation of China (11375122, 11511140277)
At the end of 2016, the first beam was extracted from the 3.0 MV Tandetron accelerator system at Sichuan University, China. The accelerator is imported from the HVEE as a multi-purpose research platform. For one of the main applications, the system will be connected to a micro-beamline to achieve submicron resolution, so the accelerator is designed with energy stability as high as 0.01%. The measured brightness for 3 MeV proton beam is 5.06 pA/um2mrad2MeV and the energy stability is reached the goal of design. The ion optic design of the microprobe beam line will be presented in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK097

Export •

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

THPAL009

A TM01 Mode Launcher With Quadrupole Field Components Cancellation for High Brightness Applications

network, GUI, quadrupole, gun

3631

G. Castorina
INFN-Roma1, Rome, Italy
A.D. Cahill, J.B. Rosenzweig
UCLA, Los Angeles, California, USA
F. Cardelli, G. Franzini, A. Marcelli, B. Spataro
INFN/LNF, Frascati (Roma), Italy
L. Celona, S. Gammino, G. Torrisi
INFN/LNS, Catania, Italy
V.A. Dolgashev
SLAC, Menlo Park, California, USA
L. Ficcadenti
Rome University La Sapienza, Roma, Italy
M. Migliorati, A. Mostacci, L. Palumbo
Sapienza University of Rome, Rome, Italy
G. Sorbello
University of Catania, Catania, Italy

The R&D of high gradient radiofrequency (RF) devices is aimed to develop innovative accelerating structures based on new manufacturing techniques and materials in order to construct devices operating with the highest accelerating gradient. Recent studies have shown a large increase in the maximum sustained RF surface electric fields in copper structures operating at cryogenic temperatures. These novel approaches allow significant performance improvements of RF photoinjectors. Indeed the operation at high surface fields results in considerable increase of electron beam brilliance. This increased brilliance requires high field quality in the RF photoinjector and specifically in its power coupler. In this work we present a novel power coupler for the RF photoinjector. The coupler is a compact X-band TM01 mode launcher with a fourfold symmetry which minimized both the dipole and the quadrupole RF components.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL009

Export •

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

THPMK118

GaN Thin Film Photocathodes for High Brightness Electron Beams

cathode, electron, target, experiment

4594

M. Vogel, X. Jiang, M. Schumacher
University Siegen, Siegen, Germany

Funding: This work was supported by the German Federal Ministry of Education and Research under grant 05K16PS1 "HOPE II: Hochbrillante photoinduzierte Hochfrequenz-Elektronenquellen".
Gallium nitride (GaN) is one promising candidate as photocathode material showing high quantum efficiencies which is one of the requirements for high brightness electron beams. In addition to reported quantum efficiencies of up to 70%, GaN needs to satisfy the demands for long lifetime, low dark current and low thermal emittance. In this contribution, the ongoing activities of the synthesis by means of reactive rf magnetron sputtering and characterization of GaN is presented. The latter is done by standard materials science methods and in-situ measurements of the quantum efficiency in combination with lifetime and dark current measurements to asses and optimize the photocathode's performance. Along with the project's details, first experimental results of GaN thin films synthesized utilizing a GaAs source are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK118

Export •

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