FLS2018 - List of Keywords (simulation)

Paper	Title	Other Keywords	Page
TUA2WB04	Ion Instability in the HEPS Storage Ring	ion, electron, storage-ring, emittance	34
	S.K. Tian, N. Wang IHEP, Beijing, People's Republic of China
	The High Energy Photon Source (HEPS), a kilometre scale storage ring light source, with a beam energy of 6 GeV and transverse emittances of a few tens of pm.rad, is to be built in Beijing and now is under design. We investigate the ion instability in the storage ring with high beam intensity and low-emittance. We performe a weak-strong simulation to show characteristic phenomena of the instability in the storage ring.
	Slides TUA2WB04 [3.446 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-TUA2WB04
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TUP1WD02	A Study on the Improved Cavity Bunch Length Monitor for FEL	ion, cavity, FEL, electron	39
	Q. Wang, X.Y. Liu, P. Lu, Q. Luo, B.G. Sun, L.L. Tang, J.H. Wei, F.F. Wu, Y.L. Yang, T.Y. Zhou, Z.R. Zhou USTC/NSRL, Hefei, Anhui, People's Republic of China
	Funding: Supported by The National Key Research and Development Program of China (2016YFA0401900), NSFC (11375178, 11575181) and the Fundamental Research Funds for the Central Universities (WK2310000046) Bunch length monitors based on cavities have great potential especially for future high quality beam sources because of many advantages such as simple structure, wide application rage, and high signal-to-noise ratio (SNR). The traditional way to measure bunch length needs two cavities at least. One is reference cavity, whose function is to get the beam intensity. The other one is defined as main cavity, which is used to calculate the bunch length. There are some drawbacks. To improve performance, the mode and the cavity shape are changed. At the same time, the position and orientation of coaxial probe are designed to avoid interference modes which come from the cavity and beam tube according to the analytic formula of the electromagnetic field distribution. A series simulation based on CST is performed to verify the feasibility, and the simulation results reveal that the improved monitor shows good performance in bunch length measurement.
	Slides TUP1WD02 [3.505 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-TUP1WD02
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEA2WD03	Analysis of Electron Trajectories in Harmonic Undulator with SCILAB's Model Based Design Codes	ion, undulator, electron, FEL	93
	H. Jeevakhan, S. Kumar NITTTR, Bhopal, India G. Mishra Devi Ahilya University, Indore, India
	Scilab's X-cos model-based simulation blocks has been used to simulate the trajectories of an electron traversing through an Harmonic undulator. The trajectory of electron along X and Y directions has been simulated from Numerical and analytical methods. Analysis given in the present paper is compared with the other codes. Parallel simulation of Harmonic undulator magnetic field along with trajectories of electron is given in the present analysis.
	Slides WEA2WD03 [0.652 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-WEA2WD03
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEP2PT021	The Design and Test of a Stripline Kicker for HEPS	ion, kicker, impedance, injection	117
	H. Shi, J. Chen, L. Huo, P. Liu, X.L. Shi, G. Wang, L. Wang, N. Wang IHEP, Beijing, People's Republic of China
	A fast stripline kicker is adopted for High Energy Photon Source (HEPS) on-axis injection. The optimization of a prototype 750 mm long kicker has been finished. The 3D simulation results show the final design of wide vane with end cover lowers the beam loss about 31% than the original design does. We develop a feedthrough model with machinable glass ceramic and achieve a VSWR under 1.3 in 0~2 GHz. The assembly of kicker and commercial feedthroughs has been tested with Keysight E5071C. The testing results of S parameters and TDR value show a good agreement with simulation ones.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-WEP2PT021
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WEP2PT034	Beyond Uniform Ellipsoidal Laser Shaping for Beam Brightness Improvements at PITZ	laser, ion, emittance, flattop	146
	H.J. Qian, J.D. Good, C. Koschitzki, M. Krasilnikov, F. Stephan DESY Zeuthen, Zeuthen, Germany
	In the last decades, photoinjector brightness has improved significantly, driven by the needs of free electron lasers and many other applications. One of the key elements is photocathode laser shaping for reducing emittance growth from nonlinear space charge forces. At the photoinjector test facility at DESY in Zeuthen (PITZ), a uniform flattop laser was used to achieve record low emittance for a bunch charge from 20 pC to 1 nC. Due to the ideal 3D space charge force linearization in ellipsoidal electron bunches, uniform ellipsoidal photocathode laser shaping were proposed to improve beam emittance up to 33% for 1 nC beam at PITZ. In this paper, we will show even further transverse emittance improvements in simulations for both flattop and ellipsoidal laser pulses with parabolic radial distribution, versus uniform distributions. The laser shaping effects on longitudinal phase space are also discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-WEP2PT034
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THA1WA03	GPT-CSR: A New Simulation Code for CSR Effects	ion, radiation, bunching, electron	157
	S.B. van der Geer, M.J. de Loos Pulsar Physics, Eindhoven, The Netherlands I. Setija, P.W. Smorenburg ASML Netherlands B.V., Veldhoven, The Netherlands P.H. Williams STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	For future applications of high-brightness electron beams, including the design of next generation FEL's, correct correct simulation of Coherent Synchrotron Radiation (CSR) is essential as it potentially degrades beam quality to unacceptable levels. However, the long interaction lengths compared to the bunch length, numerical cancellation, and difficult 3D retardation conditions make accurate simulation of CSR effects notoriously difficult. To ease the computational burden, CSR codes often make severe simplifications such as an ultra relativistic bunch travelling on a prescribed reference trajectory. Here we report on a new CSR model, implemented in the General Particle Tracer (GPT) code, that avoids most of the usual assumptions: It directly evaluates the Lienard-Wiechert potentials based on the stored history of the beam, it makes no assumptions about reference trajectories, while also taking into account the transverse size of the beam. First results demonstrating microbunching gain in a chicane are presented.
	Slides THA1WA03 [1.799 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-THA1WA03
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THP1WB02	Impedance Evaluation of PF In-Vacuum Undulator (IVU) with Theories and Simulations and Experimental Confirmation of them by the Tune Measurement	ion, impedance, undulator, vacuum	160
	O. Tanaka, N. Nakamura, T. Obina, K. Tsuchiya KEK, Ibaraki, Japan
	Four In-Vacuum Undulators (IVU) were recently installed to Photon Factory (PF) at KEK. The estimate of their impedance and kick factors is a very important issue, because they could considerably increase the total impedance of PF. Moreover, the coupling impedance of the IVUs could lead to the beam energy loss, changes in the bunch shape, betatron tune shifts and, finally, to the various beam instabilities. Using the simulation tool (CST Particle Studio), longitudinal and transverse impedances of the IVUs were evaluated and compared to analytical formulas and measurement results. The study provides guidelines for mitigation of unwanted impedance, for an accurate estimate of its effects on the beam quality and beam instabilities and for the impedance budget of a newly designed next-generation machine which has many IVUs and small-aperture beam pipes.
	Slides THP1WB02 [2.942 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-THP1WB02
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

FRA1PL01	Summary Report: Linac-Based Light Sources	ion, FEL, experiment, linac	199
	T.O. Raubenheimer SLAC, Menlo Park, California, USA W. Decking DESY, Hamburg, Germany L. Giannessi Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy L. Giannessi ENEA C.R. Frascati, Frascati (Roma), Italy H.-S. Kang PAL, Pohang, Kyungbuk, Republic of Korea
	This is the summary report of the linac-based light sources working group.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-FRA1PL01
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

TUA2WB04

Ion Instability in the HEPS Storage Ring

ion, electron, storage-ring, emittance

34

S.K. Tian, N. Wang
IHEP, Beijing, People's Republic of China

The High Energy Photon Source (HEPS), a kilometre scale storage ring light source, with a beam energy of 6 GeV and transverse emittances of a few tens of pm.rad, is to be built in Beijing and now is under design. We investigate the ion instability in the storage ring with high beam intensity and low-emittance. We performe a weak-strong simulation to show characteristic phenomena of the instability in the storage ring.

Slides TUA2WB04 [3.446 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-TUA2WB04

Export •

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

TUP1WD02

A Study on the Improved Cavity Bunch Length Monitor for FEL

ion, cavity, FEL, electron

39

Q. Wang, X.Y. Liu, P. Lu, Q. Luo, B.G. Sun, L.L. Tang, J.H. Wei, F.F. Wu, Y.L. Yang, T.Y. Zhou, Z.R. Zhou
USTC/NSRL, Hefei, Anhui, People's Republic of China

Funding: Supported by The National Key Research and Development Program of China (2016YFA0401900), NSFC (11375178, 11575181) and the Fundamental Research Funds for the Central Universities (WK2310000046)
Bunch length monitors based on cavities have great potential especially for future high quality beam sources because of many advantages such as simple structure, wide application rage, and high signal-to-noise ratio (SNR). The traditional way to measure bunch length needs two cavities at least. One is reference cavity, whose function is to get the beam intensity. The other one is defined as main cavity, which is used to calculate the bunch length. There are some drawbacks. To improve performance, the mode and the cavity shape are changed. At the same time, the position and orientation of coaxial probe are designed to avoid interference modes which come from the cavity and beam tube according to the analytic formula of the electromagnetic field distribution. A series simulation based on CST is performed to verify the feasibility, and the simulation results reveal that the improved monitor shows good performance in bunch length measurement.

Slides TUP1WD02 [3.505 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-TUP1WD02

Export •

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

WEA2WD03

Analysis of Electron Trajectories in Harmonic Undulator with SCILAB's Model Based Design Codes

ion, undulator, electron, FEL

93

H. Jeevakhan, S. Kumar
NITTTR, Bhopal, India
G. Mishra
Devi Ahilya University, Indore, India

Scilab's X-cos model-based simulation blocks has been used to simulate the trajectories of an electron traversing through an Harmonic undulator. The trajectory of electron along X and Y directions has been simulated from Numerical and analytical methods. Analysis given in the present paper is compared with the other codes. Parallel simulation of Harmonic undulator magnetic field along with trajectories of electron is given in the present analysis.

Slides WEA2WD03 [0.652 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-WEA2WD03

Export •

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

WEP2PT021

The Design and Test of a Stripline Kicker for HEPS

ion, kicker, impedance, injection

117

H. Shi, J. Chen, L. Huo, P. Liu, X.L. Shi, G. Wang, L. Wang, N. Wang
IHEP, Beijing, People's Republic of China

A fast stripline kicker is adopted for High Energy Photon Source (HEPS) on-axis injection. The optimization of a prototype 750 mm long kicker has been finished. The 3D simulation results show the final design of wide vane with end cover lowers the beam loss about 31% than the original design does. We develop a feedthrough model with machinable glass ceramic and achieve a VSWR under 1.3 in 0~2 GHz. The assembly of kicker and commercial feedthroughs has been tested with Keysight E5071C. The testing results of S parameters and TDR value show a good agreement with simulation ones.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-WEP2PT021

Export •

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

WEP2PT034

Beyond Uniform Ellipsoidal Laser Shaping for Beam Brightness Improvements at PITZ

laser, ion, emittance, flattop

146

H.J. Qian, J.D. Good, C. Koschitzki, M. Krasilnikov, F. Stephan
DESY Zeuthen, Zeuthen, Germany

In the last decades, photoinjector brightness has improved significantly, driven by the needs of free electron lasers and many other applications. One of the key elements is photocathode laser shaping for reducing emittance growth from nonlinear space charge forces. At the photoinjector test facility at DESY in Zeuthen (PITZ), a uniform flattop laser was used to achieve record low emittance for a bunch charge from 20 pC to 1 nC. Due to the ideal 3D space charge force linearization in ellipsoidal electron bunches, uniform ellipsoidal photocathode laser shaping were proposed to improve beam emittance up to 33% for 1 nC beam at PITZ. In this paper, we will show even further transverse emittance improvements in simulations for both flattop and ellipsoidal laser pulses with parabolic radial distribution, versus uniform distributions. The laser shaping effects on longitudinal phase space are also discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-WEP2PT034

Export •

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

THA1WA03

GPT-CSR: A New Simulation Code for CSR Effects

ion, radiation, bunching, electron

157

S.B. van der Geer, M.J. de Loos
Pulsar Physics, Eindhoven, The Netherlands
I. Setija, P.W. Smorenburg
ASML Netherlands B.V., Veldhoven, The Netherlands
P.H. Williams
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

For future applications of high-brightness electron beams, including the design of next generation FEL's, correct correct simulation of Coherent Synchrotron Radiation (CSR) is essential as it potentially degrades beam quality to unacceptable levels. However, the long interaction lengths compared to the bunch length, numerical cancellation, and difficult 3D retardation conditions make accurate simulation of CSR effects notoriously difficult. To ease the computational burden, CSR codes often make severe simplifications such as an ultra relativistic bunch travelling on a prescribed reference trajectory. Here we report on a new CSR model, implemented in the General Particle Tracer (GPT) code, that avoids most of the usual assumptions: It directly evaluates the Lienard-Wiechert potentials based on the stored history of the beam, it makes no assumptions about reference trajectories, while also taking into account the transverse size of the beam. First results demonstrating microbunching gain in a chicane are presented.

Slides THA1WA03 [1.799 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-THA1WA03

Export •

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

THP1WB02

Impedance Evaluation of PF In-Vacuum Undulator (IVU) with Theories and Simulations and Experimental Confirmation of them by the Tune Measurement

ion, impedance, undulator, vacuum

160

O. Tanaka, N. Nakamura, T. Obina, K. Tsuchiya
KEK, Ibaraki, Japan

Four In-Vacuum Undulators (IVU) were recently installed to Photon Factory (PF) at KEK. The estimate of their impedance and kick factors is a very important issue, because they could considerably increase the total impedance of PF. Moreover, the coupling impedance of the IVUs could lead to the beam energy loss, changes in the bunch shape, betatron tune shifts and, finally, to the various beam instabilities. Using the simulation tool (CST Particle Studio), longitudinal and transverse impedances of the IVUs were evaluated and compared to analytical formulas and measurement results. The study provides guidelines for mitigation of unwanted impedance, for an accurate estimate of its effects on the beam quality and beam instabilities and for the impedance budget of a newly designed next-generation machine which has many IVUs and small-aperture beam pipes.

Slides THP1WB02 [2.942 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-THP1WB02

Export •

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

FRA1PL01

Summary Report: Linac-Based Light Sources

ion, FEL, experiment, linac

199

T.O. Raubenheimer
SLAC, Menlo Park, California, USA
W. Decking
DESY, Hamburg, Germany
L. Giannessi
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
L. Giannessi
ENEA C.R. Frascati, Frascati (Roma), Italy
H.-S. Kang
PAL, Pohang, Kyungbuk, Republic of Korea

This is the summary report of the linac-based light sources working group.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-FRA1PL01

Export •

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