IPAC2021 - List of Authors (Qin, W.)

Paper	Title	Page
MOPAB266	Start-to-End Study on Laser and RF Jitter Effects for MAX-IV SXL	844
	S.P. Pirani, B.S. Kyle MAX IV Laboratory, Lund University, Lund, Sweden F. Curbis, M.A. Pop, S. Werin Lund University, Lund, Sweden W. Qin DESY, Hamburg, Germany
	A Soft X-ray free electron laser (FEL) for the MAX IV Laboratory is currently in the design phase and it will use the existing 3 GeV linac. Present stability limits in the RF and the photocathode laser will affect the performance of the FEL. One of the critical elements for the design of a FEL is to have an estimation on jitter effects of the accelerator parameters on the X-ray radiation. In this regard, we implemented a start-to-end study using Astra, Elegant and Genesis in order to assess possible variations in pulse energy, photon pulse length and spectral width in the Soft X-ray Laser (SXL) radiation. This investigation provides insights on the final SXL performance variation due to RF and laser related jitter affecting the electron beam.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB266
About •	paper received ※ 19 May 2021 paper accepted ※ 26 July 2021 issue date ※ 24 August 2021
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TUPAB082	Analysis of the Effect of Energy Chirp in Implementing EEHG at SXL	1566
	M.A. Pop, F. Curbis, B.S. Kyle, S.P. Pirani, W. Qin, S. Werin MAX IV Laboratory, Lund University, Lund, Sweden F. Curbis, S. Werin Lund University, Lund, Sweden W. Qin DESY, Hamburg, Germany
	As a part of the efforts to improve the longitudinal coherence in the design of the Soft X-ray FEL (the SXL) at MAX IV, we present a possible implementation of the EEHG harmonic seeding scheme partly integrated into the second bunch compressor of the existing LINAC. A special focus is given to the effect of CSR on the resulting EEHG bunching and on how this unwanted effect might be controlled.
	Poster TUPAB082 [1.825 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB082
About •	paper received ※ 15 May 2021 paper accepted ※ 28 July 2021 issue date ※ 17 August 2021
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TUPAB119	Beam Loss Study for the Implementation of Dechirper at the European XFEL	1670
	J.J. Guo University of Chinese Academy of Sciences, Beijing, People’s Republic of China W. Decking, M.W. Guetg, J.J. Guo, S. Liu, W. Qin, I. Zagorodnov DESY, Hamburg, Germany Q. Gu, J.J. Guo SINAP, Shanghai, People’s Republic of China Q. Gu Shanghai Advanced Research Institute, Pudong, Shanghai, People’s Republic of China
	The European XFEL is a free-electron laser facility based on superconducting linac with high repetition rate up to 4.5 MHz. Wakefield structure (also called dechirper module) is planned to be installed in front of the SASE beam line at the European FEL, which can be used as a kicker for two-color scheme or a dechirper to control the bandwidth of SASE radiation. When the beam pass through the dechirper module, strong longitudinal and transverse wakefields can be excited to introduce a correlated energy chirp and a kick along the bunch. However, due to the relatively small gap of dechirper, beam halo particles hitting the dechirper module can lead to energy deposition and generate additional radiation, which can cause serious damage to the downstream undulators. For this reason, simulations have been performed using BDSIM to define the maximum acceptable beam halo, and the results are presented in this paper.
	Poster TUPAB119 [1.489 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB119
About •	paper received ※ 16 May 2021 paper accepted ※ 15 June 2021 issue date ※ 12 August 2021
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TUPAB113	Highlights From the Conceptual Design Report of the Soft X-Ray Laser at MAX IV	1651
	F. Curbis, J. Andersson, L. Isaksson, B.S. Kyle, F. Lindau, E. Mansten, H. Tarawneh, P.F. Tavares, S. Thorin, A.S. Vorozhtsov MAX IV Laboratory, Lund University, Lund, Sweden S. Bonetti Stockholm University, Stockholm, Sweden V.A. Goryashko, P.M. Salén Uppsala University, Uppsala, Sweden P. Johnsson, S.P. Pirani, M.A. Pop, W. Qin, S. Werin Lund University, Lund, Sweden M. Larsson Stockholm University, Department of Physics, Stockholm, Sweden A. Nilsson FYSIKUM, AlbaNova, Stockholm University, Stockholm, Sweden J.A. Sellberg KTH Physics, Stockholm, Sweden
	Funding: Knut and Alice Wallenberg Foundation The SXL (Soft X-ray Laser) project developed a conceptual design for a soft X-ray Free Electron Laser in the 1–5 nm wavelength range, driven by the existing MAX IV 3 GeV linac. In this contribution we will focus on the FEL operation modes developed for the first phase of the project based on two different linac modes. The design work was supported by the Knut and Alice Wallenberg foundation and by several Swedish universities and organizations (Stockholm, Uppsala, KTH Royal Institute of Technology, Stockholm-Uppsala FEL center, MAX IV laboratory and Lund University).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB113
About •	paper received ※ 19 May 2021 paper accepted ※ 17 June 2021 issue date ※ 19 August 2021
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THXA04	Microbunching Instability in the Presence of Intrabeam Scattering for Single-Pass Accelerators	3692
	C.-Y. Tsai HUST, Wuhan, People’s Republic of China W. Qin Lund University, Lund, Sweden
	Funding: This work is supported by the Fundamental Research Funds for the Central Universities under Project No. 5003131049 and National Natural Science Foundation of China under project No. 11905073. Intrabeam scattering (IBS) has long been studied in lepton or hadron storage rings as a slow diffusion process, while the effects of IBS on single-pass or recirculating electron accelerators have drawn attention only in the recent two decades due to the emergence of linac-based or ERL-based 4th-generation light sources, which require high-quality electron beams during the beam transport. Recent experimental measurements indicate that in some parameter regimes, IBS can have a significant influence on microbunched beam dynamics. Here we develop a theoretical formulation* of microbunching instability (MBI) in the presence of IBS for single-pass accelerators. We start from the Vlasov-Fokker-Planck (VFP) equation, combining both collective longitudinal space charge and incoherent IBS effects. The linearized VFP equation with the corresponding coefficients is derived. The evolutions of the phase space density and energy modulations are formulated as a set of coupled integral equations. The formulation** is then applied to a simplified single-pass transport line. The results from the semi-analytical calculation are compared and show good agreement with particle tracking simulations. * C.-Y. Tsai et al., Phys. Rev. Accel. Beams 23, 124401 (2020) ** C.-Y. Tsai and W. Q, Phys. Plasmas (2021), accepted for publication
	Slides THXA04 [2.699 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THXA04
About •	paper received ※ 13 May 2021 paper accepted ※ 19 July 2021 issue date ※ 13 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Start-to-End Study on Laser and RF Jitter Effects for MAX-IV SXL

844

S.P. Pirani, B.S. Kyle
MAX IV Laboratory, Lund University, Lund, Sweden
F. Curbis, M.A. Pop, S. Werin
Lund University, Lund, Sweden
W. Qin
DESY, Hamburg, Germany

A Soft X-ray free electron laser (FEL) for the MAX IV Laboratory is currently in the design phase and it will use the existing 3 GeV linac. Present stability limits in the RF and the photocathode laser will affect the performance of the FEL. One of the critical elements for the design of a FEL is to have an estimation on jitter effects of the accelerator parameters on the X-ray radiation. In this regard, we implemented a start-to-end study using Astra, Elegant and Genesis in order to assess possible variations in pulse energy, photon pulse length and spectral width in the Soft X-ray Laser (SXL) radiation. This investigation provides insights on the final SXL performance variation due to RF and laser related jitter affecting the electron beam.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB266

About •

paper received ※ 19 May 2021 paper accepted ※ 26 July 2021 issue date ※ 24 August 2021

Export •

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

TUPAB082

Analysis of the Effect of Energy Chirp in Implementing EEHG at SXL

1566

M.A. Pop, F. Curbis, B.S. Kyle, S.P. Pirani, W. Qin, S. Werin
MAX IV Laboratory, Lund University, Lund, Sweden
F. Curbis, S. Werin
Lund University, Lund, Sweden
W. Qin
DESY, Hamburg, Germany

As a part of the efforts to improve the longitudinal coherence in the design of the Soft X-ray FEL (the SXL) at MAX IV, we present a possible implementation of the EEHG harmonic seeding scheme partly integrated into the second bunch compressor of the existing LINAC. A special focus is given to the effect of CSR on the resulting EEHG bunching and on how this unwanted effect might be controlled.

Poster TUPAB082 [1.825 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB082

About •

paper received ※ 15 May 2021 paper accepted ※ 28 July 2021 issue date ※ 17 August 2021

Export •

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

TUPAB119

Beam Loss Study for the Implementation of Dechirper at the European XFEL

1670

J.J. Guo
University of Chinese Academy of Sciences, Beijing, People’s Republic of China
W. Decking, M.W. Guetg, J.J. Guo, S. Liu, W. Qin, I. Zagorodnov
DESY, Hamburg, Germany
Q. Gu, J.J. Guo
SINAP, Shanghai, People’s Republic of China
Q. Gu
Shanghai Advanced Research Institute, Pudong, Shanghai, People’s Republic of China

The European XFEL is a free-electron laser facility based on superconducting linac with high repetition rate up to 4.5 MHz. Wakefield structure (also called dechirper module) is planned to be installed in front of the SASE beam line at the European FEL, which can be used as a kicker for two-color scheme or a dechirper to control the bandwidth of SASE radiation. When the beam pass through the dechirper module, strong longitudinal and transverse wakefields can be excited to introduce a correlated energy chirp and a kick along the bunch. However, due to the relatively small gap of dechirper, beam halo particles hitting the dechirper module can lead to energy deposition and generate additional radiation, which can cause serious damage to the downstream undulators. For this reason, simulations have been performed using BDSIM to define the maximum acceptable beam halo, and the results are presented in this paper.

Poster TUPAB119 [1.489 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB119

About •

paper received ※ 16 May 2021 paper accepted ※ 15 June 2021 issue date ※ 12 August 2021

Export •

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

TUPAB113

Highlights From the Conceptual Design Report of the Soft X-Ray Laser at MAX IV

1651

F. Curbis, J. Andersson, L. Isaksson, B.S. Kyle, F. Lindau, E. Mansten, H. Tarawneh, P.F. Tavares, S. Thorin, A.S. Vorozhtsov
MAX IV Laboratory, Lund University, Lund, Sweden
S. Bonetti
Stockholm University, Stockholm, Sweden
V.A. Goryashko, P.M. Salén
Uppsala University, Uppsala, Sweden
P. Johnsson, S.P. Pirani, M.A. Pop, W. Qin, S. Werin
Lund University, Lund, Sweden
M. Larsson
Stockholm University, Department of Physics, Stockholm, Sweden
A. Nilsson
FYSIKUM, AlbaNova, Stockholm University, Stockholm, Sweden
J.A. Sellberg
KTH Physics, Stockholm, Sweden

Funding: Knut and Alice Wallenberg Foundation
The SXL (Soft X-ray Laser) project developed a conceptual design for a soft X-ray Free Electron Laser in the 1–5 nm wavelength range, driven by the existing MAX IV 3 GeV linac. In this contribution we will focus on the FEL operation modes developed for the first phase of the project based on two different linac modes. The design work was supported by the Knut and Alice Wallenberg foundation and by several Swedish universities and organizations (Stockholm, Uppsala, KTH Royal Institute of Technology, Stockholm-Uppsala FEL center, MAX IV laboratory and Lund University).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB113

About •

paper received ※ 19 May 2021 paper accepted ※ 17 June 2021 issue date ※ 19 August 2021

Export •

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

THXA04

Microbunching Instability in the Presence of Intrabeam Scattering for Single-Pass Accelerators

3692

C.-Y. Tsai
HUST, Wuhan, People’s Republic of China
W. Qin
Lund University, Lund, Sweden

Funding: This work is supported by the Fundamental Research Funds for the Central Universities under Project No. 5003131049 and National Natural Science Foundation of China under project No. 11905073.
Intrabeam scattering (IBS) has long been studied in lepton or hadron storage rings as a slow diffusion process, while the effects of IBS on single-pass or recirculating electron accelerators have drawn attention only in the recent two decades due to the emergence of linac-based or ERL-based 4th-generation light sources, which require high-quality electron beams during the beam transport. Recent experimental measurements indicate that in some parameter regimes, IBS can have a significant influence on microbunched beam dynamics. Here we develop a theoretical formulation* of microbunching instability (MBI) in the presence of IBS for single-pass accelerators. We start from the Vlasov-Fokker-Planck (VFP) equation, combining both collective longitudinal space charge and incoherent IBS effects. The linearized VFP equation with the corresponding coefficients is derived. The evolutions of the phase space density and energy modulations are formulated as a set of coupled integral equations. The formulation** is then applied to a simplified single-pass transport line. The results from the semi-analytical calculation are compared and show good agreement with particle tracking simulations.
* C.-Y. Tsai et al., Phys. Rev. Accel. Beams 23, 124401 (2020)
** C.-Y. Tsai and W. Q, Phys. Plasmas (2021), accepted for publication

Slides THXA04 [2.699 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THXA04

About •

paper received ※ 13 May 2021 paper accepted ※ 19 July 2021 issue date ※ 13 August 2021

Export •

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