IPAC2021 - List of Authors (Liu, S.)

Paper	Title	Page
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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TUPAB125	Studies of Particle Losses From the Beam in the EU-XFEL Following Scattering by a Slotted Foil	1681
	A.T. Potter, A. Wolski The University of Liverpool, Liverpool, United Kingdom W. Decking, S. Liu DESY, Hamburg, Germany F. Jackson STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	One technique for producing short radiation pulses in an FEL involves the use of a slotted foil in a bunch compressor. However, the scattering of particles from the foil can lead to increased particle losses and the generation of secondary particles. This is a particular concern for high rep-rate FELs, such as the European XFEL, where there are plans to implement the slotted-foil technique for short pulse generation. The study reported here aims to characterise the impact of a slotted foil in the European XFEL on the radiation dose in the front section of one of the undulators. Simulations were performed using BDSIM: this code tracks primary particles along the beamline, models the interaction between particles and accelerator components and tracks secondary particles produced by these interactions. The results indicate the amount of energy deposited in the front section of one of the FEL undulators, and provide a basis for optimisation of the collimation system to keep the energy deposition and radiation doses within acceptable limits.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB125
About •	paper received ※ 19 May 2021 paper accepted ※ 10 June 2021 issue date ※ 28 August 2021
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WEPAB132	Towards a Superconducting Undulator Afterburner for the European XFEL	2921
	S. Casalbuoni, J.E. Baader, G. Geloni, V. Grattoni, D. La Civita, C. Lechner, B. Marchetti, S. Serkez, H. Sinn EuXFEL, Schenefeld, Germany W. Decking, L. Lilje, S. Liu, T. Wohlenberg, I. Zagorodnov DESY, Hamburg, Germany
	We propose to develop, characterize and operate a superconducting undulator (SCU) afterburner consisting of 5 undulator modules (1 module = 2 times SCU coil of 2 m length and 1 phase shifter) at the SASE2 hard X-ray beamline of European XFEL. This afterburner has the potential to produce an output of more than 10¹⁰ ph/pulse at photon energies above 30 keV. The project is divided into the production of a pre-series prototype module and a small-series production of 5 modules. Central goals of this R&D activity are: the demonstration of the functionality of SCUs at an X-ray FEL, the set up of the needed infrastructure to characterize and operate SCUs, the industrialization of such undulators, and the reduction of the price per module. In this contribution, the main parameters and specifications of the pre-series prototype module (S-PRESSO) are described.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB132
About •	paper received ※ 15 May 2021 paper accepted ※ 05 July 2021 issue date ※ 14 August 2021
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THPAB214	Recent BDSIM Related Developments and Modeling of Accelerators	4208
	L.J. Nevay, A. Abramov, S.E. Alden, S.T. Boogert, G. D’Alessandro, S.M. Gibson, H. Lefebvre, W. Shields, S.D. Walker JAI, Egham, Surrey, United Kingdom A. Abramov, G. D’Alessandro, C. Hernalsteens CERN, Meyrin, Switzerland E. Gnacadja, C. Hernalsteens, E. Ramoisiaux, R. Tesse ULB, Bruxelles, Belgium S. Liu DESY, Hamburg, Germany
	Funding: This work is supported by the STFC (UK) grants: JAI ST/P00203X/1, HL-LHC-UK1 ST/N001583/1, HL-LHC-UK2 ST/T001925/1, and ST/P003028/1. Beam Delivery Simulation (BDSIM) is a program based on Geant4 that creates 3D radiation transport models of accelerators from a simple optical description in a vastly reduced time frame with great flexibility. It also uses ROOT and CLHEP to create a single simulation model that can accurately track all particle species in an accelerator to predict and understand beam losses, secondary radiation, dosimetric quantities and their origin. BDSIM provides a library of scalable generic geometry for a variety of applications. Our Python package, Pyg4ometry, allows rapid preparation and conversion of geometries for BDSIM and other radiation transport simulations including FLUKA. We present a broad overview of BDSIM developments related to a variety of experiments at several facilities. We present a model of the forward experiment FASER at the LHC, CERN where the geometry is composited from multiple sources using Pyg4ometry. The analysis of particle history is presented as well as production mechanisms. We also present the application of recently introduced laser interactions in Geant4 to Compton photons from a laserwire diagnostic at the ATF2.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB214
About •	paper received ※ 20 May 2021 paper accepted ※ 19 July 2021 issue date ※ 22 August 2021
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Paper

Title

Page

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)

TUPAB125

Studies of Particle Losses From the Beam in the EU-XFEL Following Scattering by a Slotted Foil

1681

A.T. Potter, A. Wolski
The University of Liverpool, Liverpool, United Kingdom
W. Decking, S. Liu
DESY, Hamburg, Germany
F. Jackson
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

One technique for producing short radiation pulses in an FEL involves the use of a slotted foil in a bunch compressor. However, the scattering of particles from the foil can lead to increased particle losses and the generation of secondary particles. This is a particular concern for high rep-rate FELs, such as the European XFEL, where there are plans to implement the slotted-foil technique for short pulse generation. The study reported here aims to characterise the impact of a slotted foil in the European XFEL on the radiation dose in the front section of one of the undulators. Simulations were performed using BDSIM: this code tracks primary particles along the beamline, models the interaction between particles and accelerator components and tracks secondary particles produced by these interactions. The results indicate the amount of energy deposited in the front section of one of the FEL undulators, and provide a basis for optimisation of the collimation system to keep the energy deposition and radiation doses within acceptable limits.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB125

About •

paper received ※ 19 May 2021 paper accepted ※ 10 June 2021 issue date ※ 28 August 2021

Export •

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

WEPAB132

Towards a Superconducting Undulator Afterburner for the European XFEL

2921

S. Casalbuoni, J.E. Baader, G. Geloni, V. Grattoni, D. La Civita, C. Lechner, B. Marchetti, S. Serkez, H. Sinn
EuXFEL, Schenefeld, Germany
W. Decking, L. Lilje, S. Liu, T. Wohlenberg, I. Zagorodnov
DESY, Hamburg, Germany

We propose to develop, characterize and operate a superconducting undulator (SCU) afterburner consisting of 5 undulator modules (1 module = 2 times SCU coil of 2 m length and 1 phase shifter) at the SASE2 hard X-ray beamline of European XFEL. This afterburner has the potential to produce an output of more than 10¹⁰ ph/pulse at photon energies above 30 keV. The project is divided into the production of a pre-series prototype module and a small-series production of 5 modules. Central goals of this R&D activity are: the demonstration of the functionality of SCUs at an X-ray FEL, the set up of the needed infrastructure to characterize and operate SCUs, the industrialization of such undulators, and the reduction of the price per module. In this contribution, the main parameters and specifications of the pre-series prototype module (S-PRESSO) are described.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB132

About •

paper received ※ 15 May 2021 paper accepted ※ 05 July 2021 issue date ※ 14 August 2021

Export •

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

THPAB214

Recent BDSIM Related Developments and Modeling of Accelerators

4208

L.J. Nevay, A. Abramov, S.E. Alden, S.T. Boogert, G. D’Alessandro, S.M. Gibson, H. Lefebvre, W. Shields, S.D. Walker
JAI, Egham, Surrey, United Kingdom
A. Abramov, G. D’Alessandro, C. Hernalsteens
CERN, Meyrin, Switzerland
E. Gnacadja, C. Hernalsteens, E. Ramoisiaux, R. Tesse
ULB, Bruxelles, Belgium
S. Liu
DESY, Hamburg, Germany

Funding: This work is supported by the STFC (UK) grants: JAI ST/P00203X/1, HL-LHC-UK1 ST/N001583/1, HL-LHC-UK2 ST/T001925/1, and ST/P003028/1.
Beam Delivery Simulation (BDSIM) is a program based on Geant4 that creates 3D radiation transport models of accelerators from a simple optical description in a vastly reduced time frame with great flexibility. It also uses ROOT and CLHEP to create a single simulation model that can accurately track all particle species in an accelerator to predict and understand beam losses, secondary radiation, dosimetric quantities and their origin. BDSIM provides a library of scalable generic geometry for a variety of applications. Our Python package, Pyg4ometry, allows rapid preparation and conversion of geometries for BDSIM and other radiation transport simulations including FLUKA. We present a broad overview of BDSIM developments related to a variety of experiments at several facilities. We present a model of the forward experiment FASER at the LHC, CERN where the geometry is composited from multiple sources using Pyg4ometry. The analysis of particle history is presented as well as production mechanisms. We also present the application of recently introduced laser interactions in Geant4 to Compton photons from a laserwire diagnostic at the ATF2.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB214

About •

paper received ※ 20 May 2021 paper accepted ※ 19 July 2021 issue date ※ 22 August 2021

Export •

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