SAP2023 - List of Authors (Shi, J.R.)

Paper	Title	Page
MOIAA01	Progress of steady-state microbunching research
	R.K. Li, H.B. Chen, L.W. Chen, X.J. Deng, Y.C. Du, P.W. Huang, W.-H. Huang, Z.Z. Li, X. Liu, Z. Pan, J.R. Shi, C.-X. Tang, H. Wang, L.X. Yan TUB, Beijing, People’s Republic of China
	Funding: Work supported by the National Key Research and Development Program of China No. 2022YFA1603400 and the Tsinghua University Initiative Scientific Research Program No. 20197050028, 20191081195. Steady-state microbunching (SSMB) is a new concept radiation-generation mechanism that utilizes laser and a specially designed magnetic lattice to create and maintain fine structures in a high-quality electron beam for coherent light emission [1]. The SSMB concept combines major advantages of conventional synchrotron light sources and linac-based free-electron lasers. It opens up a rich field for beam dynamics research and holds tremendous potential as one of the candidate options for next-generation light source for advanced semiconductor fabrication. The proof-of-principle demonstration experiment of SSMB has been accomplished [2]. R&D on a complete dedicated SSMB facility is currently underway [3]. In this talk, we will report on the progress on the beam dynamics design and optimization, as well as the key components including the laser enhancement cavity and electron injector of a SSMB light source. [1] Phys. Rev. Lett. 105, 154801 (2010) [2] Nature 590, 576¿579 (2021). [3] Acta Phys. Sin. 71, 152901 (2022).
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MOPB008	Approximation of Space Charge Effect in the Presence of Longitudinal Magnetic Fields	27
	H.Y. Li, H.B. Chen, Q. Gao, W.H. Gu, J.R. Shi, H. Zha TUB, Beijing, People’s Republic of China
	The space charge effect plays a significant role in the evolution of phase space during beam transport. Applying an external longitudinal magnetic field has been shown to effectively reduce beam expansion through the mechanism of beam rotation. In this article, we present a fast approximation algorithm for estimating the impact of an external magnetic field on beam expansion. The algorithm enables efficient computations and provides insights into controlling the phase space dynamics of the beam in the presence of longitudinal magnetic fields.
	Poster MOPB008 [0.447 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB008
About •	Received ※ 30 June 2023 — Revised ※ 11 July 2023 — Accepted ※ 12 July 2023 — Issued ※ 30 April 2024
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TUCYA01	Development and application of ultrahigh vacuum S-band RF gun
	P.W. Huang, H.B. Chen, Y.C. Du, W.-H. Huang, R.K. Li, J.R. Shi, C.-X. Tang, X.-Y. Zhang, L.M. Zheng TUB, Beijing, People’s Republic of China
	Funding: The work was partially supported by the National Key Research and Development Program of China No. 2022YFA1603400. Next generation of electron sources require higher electric field gradient and lower thermal emittance photocathodes. Recently, a series of high quantum efficiency, low thermal emittance and visible light driven advanced photocathodes have been developed, while they are sensitive to the vacuum condition. The previous studies on these advanced photocathodes are carried out at low gradient gun and the performances at the high gradient gun require comprehensive investigations. We developed an ultrahigh vacuum S-band RF gun to accommodate the vacuum sensitive photocathodes. The gun serves as a platform for high gradient studies on advanced photocathodes and is promising to advance the frontier of the electron beam brightness. This report will introduce the development of the ultrahigh vacuum S-band gun and the corresponding load lock system and advanced photocathode deposition system.
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TUPB013	Multipole Field Optimization of X-Band High Gradient Structure	108
	B.Y. Feng, H.B. Chen, Q. Gao, X. Lin, J.R. Shi, H. Zha TUB, Beijing, People’s Republic of China
	The X-band constant gradient acceleration structure plays a crucial role in the VIGAS project. However, the presence of a multipole field component in the struc-ture’s coupler leads to an increase in ray bandwidth and a decrease in yield, ultimately affecting the quality of the generated rays. Through calculations, it has been determined that the quadrupole field component is particularly prominent in the original structure, ac-counting for 29.5% of the fundamental mode strength. Therefore, it is necessary to modify the cavity struc-ture of the coupler. By altering the shape of the cavity to two staggered circles, the objective of reducing the quadrupole field is achieved. The optimized quadru-pole field component now accounts for approximately 0.3% of the fundamental mode strength. Subsequently, the non-resonant perturbation method was employed to simulate and experimentally measure the magnitude of the multipole field component in the actual acceler-ation cavity.
	Poster TUPB013 [0.350 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SAP2023-TUPB013
About •	Received ※ 30 June 2023 — Accepted ※ 11 July 2023 — Issued ※ 27 September 2024
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

MOIAA01

Progress of steady-state microbunching research

R.K. Li, H.B. Chen, L.W. Chen, X.J. Deng, Y.C. Du, P.W. Huang, W.-H. Huang, Z.Z. Li, X. Liu, Z. Pan, J.R. Shi, C.-X. Tang, H. Wang, L.X. Yan
TUB, Beijing, People’s Republic of China

Funding: Work supported by the National Key Research and Development Program of China No. 2022YFA1603400 and the Tsinghua University Initiative Scientific Research Program No. 20197050028, 20191081195.
Steady-state microbunching (SSMB) is a new concept radiation-generation mechanism that utilizes laser and a specially designed magnetic lattice to create and maintain fine structures in a high-quality electron beam for coherent light emission [1]. The SSMB concept combines major advantages of conventional synchrotron light sources and linac-based free-electron lasers. It opens up a rich field for beam dynamics research and holds tremendous potential as one of the candidate options for next-generation light source for advanced semiconductor fabrication. The proof-of-principle demonstration experiment of SSMB has been accomplished [2]. R&D on a complete dedicated SSMB facility is currently underway [3]. In this talk, we will report on the progress on the beam dynamics design and optimization, as well as the key components including the laser enhancement cavity and electron injector of a SSMB light source.
[1] Phys. Rev. Lett. 105, 154801 (2010)
[2] Nature 590, 576¿579 (2021).
[3] Acta Phys. Sin. 71, 152901 (2022).

Cite •

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

MOPB008

Approximation of Space Charge Effect in the Presence of Longitudinal Magnetic Fields

27

H.Y. Li, H.B. Chen, Q. Gao, W.H. Gu, J.R. Shi, H. Zha
TUB, Beijing, People’s Republic of China

The space charge effect plays a significant role in the evolution of phase space during beam transport. Applying an external longitudinal magnetic field has been shown to effectively reduce beam expansion through the mechanism of beam rotation. In this article, we present a fast approximation algorithm for estimating the impact of an external magnetic field on beam expansion. The algorithm enables efficient computations and provides insights into controlling the phase space dynamics of the beam in the presence of longitudinal magnetic fields.

Poster MOPB008 [0.447 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB008

About •

Received ※ 30 June 2023 — Revised ※ 11 July 2023 — Accepted ※ 12 July 2023 — Issued ※ 30 April 2024

Cite •

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

TUCYA01

Development and application of ultrahigh vacuum S-band RF gun

P.W. Huang, H.B. Chen, Y.C. Du, W.-H. Huang, R.K. Li, J.R. Shi, C.-X. Tang, X.-Y. Zhang, L.M. Zheng
TUB, Beijing, People’s Republic of China

Funding: The work was partially supported by the National Key Research and Development Program of China No. 2022YFA1603400.
Next generation of electron sources require higher electric field gradient and lower thermal emittance photocathodes. Recently, a series of high quantum efficiency, low thermal emittance and visible light driven advanced photocathodes have been developed, while they are sensitive to the vacuum condition. The previous studies on these advanced photocathodes are carried out at low gradient gun and the performances at the high gradient gun require comprehensive investigations. We developed an ultrahigh vacuum S-band RF gun to accommodate the vacuum sensitive photocathodes. The gun serves as a platform for high gradient studies on advanced photocathodes and is promising to advance the frontier of the electron beam brightness. This report will introduce the development of the ultrahigh vacuum S-band gun and the corresponding load lock system and advanced photocathode deposition system.

Cite •

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

TUPB013

Multipole Field Optimization of X-Band High Gradient Structure

108

B.Y. Feng, H.B. Chen, Q. Gao, X. Lin, J.R. Shi, H. Zha
TUB, Beijing, People’s Republic of China

The X-band constant gradient acceleration structure plays a crucial role in the VIGAS project. However, the presence of a multipole field component in the struc-ture’s coupler leads to an increase in ray bandwidth and a decrease in yield, ultimately affecting the quality of the generated rays. Through calculations, it has been determined that the quadrupole field component is particularly prominent in the original structure, ac-counting for 29.5% of the fundamental mode strength. Therefore, it is necessary to modify the cavity struc-ture of the coupler. By altering the shape of the cavity to two staggered circles, the objective of reducing the quadrupole field is achieved. The optimized quadru-pole field component now accounts for approximately 0.3% of the fundamental mode strength. Subsequently, the non-resonant perturbation method was employed to simulate and experimentally measure the magnitude of the multipole field component in the actual acceler-ation cavity.

Poster TUPB013 [0.350 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SAP2023-TUPB013

About •

Received ※ 30 June 2023 — Accepted ※ 11 July 2023 — Issued ※ 27 September 2024

Cite •

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