SAP2023 - List of Keywords (FEL)

Paper	Title	Other Keywords	Page
MOPB026	Physical Design for EEHG Beamlines at S3FEL	electron, undulator, radiation, simulation	55
	X.F. Wang Institute of Advanced Science Facilities, Shenzhen, People’s Republic of China C. Feng, Z. Wang SARI-CAS, Pudong, Shanghai, People’s Republic of China X.M. Li, J.T. Sun, Y. Yu DICP, Dalian, Liaoning, People’s Republic of China Y.F. Liang, X.M. Yang, H. Yi, L. Zeng, W.Q. Zhang IASF, Shenzhen, Guangdong, People’s Republic of China
	Funding: Work supported by the National Key R&D Program of China (Grant No.2018YFE0203000) and the National Natural Science Foundation of China (Grant No.22288201). The proposed Shenzhen Superconducting Soft X-Ray Free-electron Laser (S3FEL) aims at generating FEL pulses from 1 nm to 30 nm. At phase-I, two undulator beamlines work at ehco-enable harmonic generation (EEHG) principle. The two undulators will cover the spectral ranges 2.3-15 nm (~83-539 eV) and 5-30 nm (~41-248 eV), respectively, when receiving electrons from 2.5 GeV superconducting linac. However, the generated FEL radiation is sensitive to various electron beam properties, e.g., its energy profile influenced by collective effects such as Coherent Synchroton Radiation (CSR), especially at high harmonics. To generate intense full coherent FEL radiation at ultra-short wavelength, a novel technique of EEHG cascaded harmonic lasing method is also considered. Physical design and FEL performance are described in this paper.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB026
About •	Received ※ 10 July 2023 — Revised ※ 11 July 2023 — Accepted ※ 18 July 2023 — Issued ※ 04 October 2024
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPB027	A Scheme of Fully Coherent X-Ray Free Electron Laser for the Shine Based on Fresh-Slices	electron, radiation, undulator, simulation	59
	YX. Liu SINAP, Shanghai, People’s Republic of China T. Liu SARI-CAS, Pudong, Shanghai, People’s Republic of China
	In this paper, the fresh-slice self-seeding free electron laser scheme is studied, and the feasibility of its application in the SHINE project is analyzed. The scheme used the fresh-slice method to generate the beam with adjustable spatial distribution, which can effectively improve the longitudinal coherence and stability of the self-seeding output radiation. Through the FEL simulation, we demonstrated that this scheme can produce a highly stable, narrow bandwidth pulse output under the SHINE’s parametric conditions, which will be beneficial to further improve the performance of this device in the future.
	Poster MOPB027 [1.524 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB027
About •	Received ※ 10 July 2023 — Revised ※ 11 July 2023 — Accepted ※ 12 July 2023 — Issued ※ 02 November 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPB029	Multi-bunch Operation Mode for Simultaneously Serving SASE and Seeding FEL Beamlines	electron, acceleration, undulator, laser	66
	X.F. Wang Institute of Advanced Science Facilities, Shenzhen, People’s Republic of China X.M. Li, J.T. Sun, X.M. Yang, Y. Yu, W.Q. Zhang DICP, Dalian, Liaoning, People’s Republic of China Y.F. Liang, X.M. Yang, H. Yi, L. Zeng, W.Q. Zhang IASF, Shenzhen, Guangdong, People’s Republic of China
	Modern free-electron laser (FEL) facilities are de-signed to simultaneously serve multiple undulator lines to provide x-ray pulses with high peak power and tunable wavelengths. To satisfy different scientific demands, it is preferred to make the separate undulator lines work under different FEL schemes, such as the self-amplified spontaneous emission (SASE) scheme and the echo-enabled harmonic generation (EEHG) scheme. However, different FEL schemes have differ-ent requirements on the beam longitudinal distribu-tion. Here, we propose to use multiple bunches to sim-ultaneously serve the undulator lines and put the bunches at different acceleration phase to change the bunch length with two compressor chicanes. The ac-celeration phase for each bunch is varied by adjusting the time delays of the photocathode drive laser pulses with the accelerator settings unchanged. The start-to-end simulation demonstrates that a fs bunch with high peak current can be produced to serve the SASE line while a bunch with hundred-of-fs length and uniform current distribution can be produced to serve the EEHG line. The FEL performances are simulated and discussed.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB029
About •	Received ※ 25 June 2023 — Revised ※ 10 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 07 September 2024
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPB034	Start to End Simulation for A Compact THz-FEL	electron, undulator, cavity, radiation	76
	R.Y. Luo, Q.S. Chen HUST, Wuhan, People’s Republic of China
	Funding: This work is supported by the National Natural Science Foundation of China(No.12175077) An oscillator type terahertz free electron laser (THz-FEL) is under construction at Huazhong University of Science and Technology (HUST). The designed electron beam energy ranges from 8 MeV to 14 MeV, and the radiation frequency ranges from 3 THz to 10 THz. FEL requires high quality electron beams of emittance, energy spread, bunch charge etc. To know the overall facility performance, a start to end simulation (from electron gun to the end of the oscillator) of the THz-FEL is performed. The simulation of the electron gun to the exit of the linac is performed using PARMELA, where the effect of space charge effects is considered. In addition, the effect of beam loading effect is considered for the linac. The transport line is matched and simulated using ELEGANT. GENESIS 1.3 and OPC is used for the lasing process. Results of the simulation are presented and discussed in this paper.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB034
About •	Received ※ 30 June 2023 — Revised ※ 08 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 18 October 2024
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPB029	Wakefield Studies for the Step Structure and the Skin Depth of Coated Dielectric Tubes	wakefield, electron, impedance, simulation	147
	H. Liu SINAP, Shanghai, People’s Republic of China S. Chen, H.X. Deng, B. Liu, Y.M. Wen SARI-CAS, Pudong, Shanghai, People’s Republic of China J.J. Guo Zhangjiang Lab, Shanghai, People’s Republic of China
	Funding: This work was supported by YSBR-042, 12125508, 11935020, 21XD1404100 and JCYJ-SHFY-2021-010. Wakefield issues are always important research objects in free electron laser (FEL) facilities. Since the wakefield in free electron laser facilities usually leads to a decrease of FEL performance, the research of the wakefield impacts is of great significance. Step structures are almost ubiquitous in the overall undulator section of an FEL facility, which always generate critical wakefields. In this paper, we systematically analyze and summarize the wakefield characteristics of step structures including the step-in structure and the step-out structure. In addition, the skin depth issue of the wakefield is still controversial. We study the skin depth of the wakefield field in the vacuum chamber of the kicker in the SHINE, which is made of the dielectric pipe. We proposed the conception of ¿effective skin depth¿ from two different perspectives and wrote simulation codes to calculate the ¿effective skin depth¿. We hope these methods could provide new mentalities for related research in the future.
	Poster TUPB029 [0.392 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SAP2023-TUPB029
About •	Received ※ 30 June 2023 — Revised ※ 09 July 2023 — Accepted ※ 12 July 2023 — Issued ※ 21 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

MOPB026

Physical Design for EEHG Beamlines at S3FEL

electron, undulator, radiation, simulation

55

X.F. Wang
Institute of Advanced Science Facilities, Shenzhen, People’s Republic of China
C. Feng, Z. Wang
SARI-CAS, Pudong, Shanghai, People’s Republic of China
X.M. Li, J.T. Sun, Y. Yu
DICP, Dalian, Liaoning, People’s Republic of China
Y.F. Liang, X.M. Yang, H. Yi, L. Zeng, W.Q. Zhang
IASF, Shenzhen, Guangdong, People’s Republic of China

Funding: Work supported by the National Key R&D Program of China (Grant No.2018YFE0203000) and the National Natural Science Foundation of China (Grant No.22288201).
The proposed Shenzhen Superconducting Soft X-Ray Free-electron Laser (S3FEL) aims at generating FEL pulses from 1 nm to 30 nm. At phase-I, two undulator beamlines work at ehco-enable harmonic generation (EEHG) principle. The two undulators will cover the spectral ranges 2.3-15 nm (~83-539 eV) and 5-30 nm (~41-248 eV), respectively, when receiving electrons from 2.5 GeV superconducting linac. However, the generated FEL radiation is sensitive to various electron beam properties, e.g., its energy profile influenced by collective effects such as Coherent Synchroton Radiation (CSR), especially at high harmonics. To generate intense full coherent FEL radiation at ultra-short wavelength, a novel technique of EEHG cascaded harmonic lasing method is also considered. Physical design and FEL performance are described in this paper.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB026

About •

Received ※ 10 July 2023 — Revised ※ 11 July 2023 — Accepted ※ 18 July 2023 — Issued ※ 04 October 2024

Cite •

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

MOPB027

A Scheme of Fully Coherent X-Ray Free Electron Laser for the Shine Based on Fresh-Slices

electron, radiation, undulator, simulation

59

YX. Liu
SINAP, Shanghai, People’s Republic of China
T. Liu
SARI-CAS, Pudong, Shanghai, People’s Republic of China

In this paper, the fresh-slice self-seeding free electron laser scheme is studied, and the feasibility of its application in the SHINE project is analyzed. The scheme used the fresh-slice method to generate the beam with adjustable spatial distribution, which can effectively improve the longitudinal coherence and stability of the self-seeding output radiation. Through the FEL simulation, we demonstrated that this scheme can produce a highly stable, narrow bandwidth pulse output under the SHINE’s parametric conditions, which will be beneficial to further improve the performance of this device in the future.

Poster MOPB027 [1.524 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB027

About •

Received ※ 10 July 2023 — Revised ※ 11 July 2023 — Accepted ※ 12 July 2023 — Issued ※ 02 November 2023

Cite •

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

MOPB029

Multi-bunch Operation Mode for Simultaneously Serving SASE and Seeding FEL Beamlines

electron, acceleration, undulator, laser

66

X.F. Wang
Institute of Advanced Science Facilities, Shenzhen, People’s Republic of China
X.M. Li, J.T. Sun, X.M. Yang, Y. Yu, W.Q. Zhang
DICP, Dalian, Liaoning, People’s Republic of China
Y.F. Liang, X.M. Yang, H. Yi, L. Zeng, W.Q. Zhang
IASF, Shenzhen, Guangdong, People’s Republic of China

Modern free-electron laser (FEL) facilities are de-signed to simultaneously serve multiple undulator lines to provide x-ray pulses with high peak power and tunable wavelengths. To satisfy different scientific demands, it is preferred to make the separate undulator lines work under different FEL schemes, such as the self-amplified spontaneous emission (SASE) scheme and the echo-enabled harmonic generation (EEHG) scheme. However, different FEL schemes have differ-ent requirements on the beam longitudinal distribu-tion. Here, we propose to use multiple bunches to sim-ultaneously serve the undulator lines and put the bunches at different acceleration phase to change the bunch length with two compressor chicanes. The ac-celeration phase for each bunch is varied by adjusting the time delays of the photocathode drive laser pulses with the accelerator settings unchanged. The start-to-end simulation demonstrates that a fs bunch with high peak current can be produced to serve the SASE line while a bunch with hundred-of-fs length and uniform current distribution can be produced to serve the EEHG line. The FEL performances are simulated and discussed.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB029

About •

Received ※ 25 June 2023 — Revised ※ 10 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 07 September 2024

Cite •

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

MOPB034

Start to End Simulation for A Compact THz-FEL

electron, undulator, cavity, radiation

76

R.Y. Luo, Q.S. Chen
HUST, Wuhan, People’s Republic of China

Funding: This work is supported by the National Natural Science Foundation of China(No.12175077)
An oscillator type terahertz free electron laser (THz-FEL) is under construction at Huazhong University of Science and Technology (HUST). The designed electron beam energy ranges from 8 MeV to 14 MeV, and the radiation frequency ranges from 3 THz to 10 THz. FEL requires high quality electron beams of emittance, energy spread, bunch charge etc. To know the overall facility performance, a start to end simulation (from electron gun to the end of the oscillator) of the THz-FEL is performed. The simulation of the electron gun to the exit of the linac is performed using PARMELA, where the effect of space charge effects is considered. In addition, the effect of beam loading effect is considered for the linac. The transport line is matched and simulated using ELEGANT. GENESIS 1.3 and OPC is used for the lasing process. Results of the simulation are presented and discussed in this paper.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB034

About •

Received ※ 30 June 2023 — Revised ※ 08 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 18 October 2024

Cite •

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

TUPB029

Wakefield Studies for the Step Structure and the Skin Depth of Coated Dielectric Tubes

wakefield, electron, impedance, simulation

147

H. Liu
SINAP, Shanghai, People’s Republic of China
S. Chen, H.X. Deng, B. Liu, Y.M. Wen
SARI-CAS, Pudong, Shanghai, People’s Republic of China
J.J. Guo
Zhangjiang Lab, Shanghai, People’s Republic of China

Funding: This work was supported by YSBR-042, 12125508, 11935020, 21XD1404100 and JCYJ-SHFY-2021-010.
Wakefield issues are always important research objects in free electron laser (FEL) facilities. Since the wakefield in free electron laser facilities usually leads to a decrease of FEL performance, the research of the wakefield impacts is of great significance. Step structures are almost ubiquitous in the overall undulator section of an FEL facility, which always generate critical wakefields. In this paper, we systematically analyze and summarize the wakefield characteristics of step structures including the step-in structure and the step-out structure. In addition, the skin depth issue of the wakefield is still controversial. We study the skin depth of the wakefield field in the vacuum chamber of the kicker in the SHINE, which is made of the dielectric pipe. We proposed the conception of ¿effective skin depth¿ from two different perspectives and wrote simulation codes to calculate the ¿effective skin depth¿. We hope these methods could provide new mentalities for related research in the future.

Poster TUPB029 [0.392 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SAP2023-TUPB029

About •

Received ※ 30 June 2023 — Revised ※ 09 July 2023 — Accepted ※ 12 July 2023 — Issued ※ 21 September 2023

Cite •

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