FLS2023 - List of Authors (Deng, X.J.)

Paper	Title	Page
TU1B2	Low-alpha Storage Ring Design for Steady-State Microbunching to Generate EUV Radiation
	Z. Pan, A. Chao, X.J. Deng, W.-H. Huang, R.K. Li, Z.Z. Li, C.-X. Tang TUB, Beijing, People’s Republic of China
	A new concept is proposed for minimizing the longitudinal emittance of a low momentum compaction factor (low-alpha) storage ring which has the capability to stably store sub-femtosecond electron bunches for the first time. This storage ring is designed for Steady-State microbunching (SSMB) to generate kW level average power EUV radiation. The proposed design approach can be applied to any quasi-isochronous storage rings to yield very high radiation power due to longitudinal coherence of the radiation. We obtain an optimal lattice design by minimizing global and local momentum compaction factors simultaneously and the result of single-particle tracking shows that the electron beam with equilibrium rms bunch length of about 40 nm can be stored in this ring. We also clarify in this type ring, the horizontal emittance will be fixed when beam energy, dipole bending angle and cell tune is fixed. In this type ring, the calculation for IBS effect will be different with traditional rings, we point out where the difference is and give a more convenient calculation for it.
	Slides TU1B2 [1.628 MB]
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TU4P28	Useful Formulas and Example Parameters Set for the Design of SSMB Storage Rings	135
	X.J. Deng, A. Chao, W.-H. Huang, Z.Z. Li, Z. Pan, C.-X. Tang TUB, Beijing, People’s Republic of China
	A promising accelerator light source mechanism called steady-state microbunching (SSMB) has been actively studied in recent years. Here we summarize some important formulas for the design of SSMB storage rings. Generally we group our formulas into two categories, i.e., a longitudinal weak focusing storage ring for a desired radiation wavelength larger than 100 nm, and a transverse-longitudinal coupling, or a generalized longitudinal strong focusing, storage ring for a desired radiation wavelength between 1 nm and 100 nm. In each category, we have presented an example parameters set for the corresponding SSMB storage ring, to generate kW-level infrared, EUV and soft X-ray radiation, respectively.
DOI •	reference for this paper ※ doi:10.18429/JACoW-FLS2023-TU4P28
About •	Received ※ 15 August 2023 — Revised ※ 24 August 2023 — Accepted ※ 30 August 2023 — Issued ※ 02 December 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TU4P29	Why is the Coherent Radiation from Laser-induced Microbunches Narrowbanded and Collimated	139
	X.J. Deng, A. Chao TUB, Beijing, People’s Republic of China
	There are two reasons: one is the long coherence length of radiation from micobunches imprinted by the modulation laser, the second is the finite transverse electron beam size. In other words, one is due to the longitudinal form factor, and the other the transverse form factor of the electron beam. Here we study the role of these form factors in shaping the energy spectrum and spatial distribution of microbunching radiation. The investigations are of value for cases like steady-state microbunching (SSMB), coherent harmonic generation (CHG) and free-electron laser (FEL).
DOI •	reference for this paper ※ doi:10.18429/JACoW-FLS2023-TU4P29
About •	Received ※ 14 August 2023 — Revised ※ 24 August 2023 — Accepted ※ 30 August 2023 — Issued ※ 02 December 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TU4P30	Optical Stochastic Cooling in a General Coupled Lattice	143
	X.J. Deng TUB, Beijing, People’s Republic of China
	Here we present a formalism of optical stochastic cooling in a 3D general coupled lattice. The formalism is general, and can treat a variety of damping and diffusion mechanisms within a single framework. We expect the work to be of value for the development of future light source.
DOI •	reference for this paper ※ doi:10.18429/JACoW-FLS2023-TU4P30
About •	Received ※ 15 August 2023 — Revised ※ 24 August 2023 — Accepted ※ 30 August 2023 — Issued ※ 02 December 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TU4P31	A Recursive Model for Laser-Electron-Radiation Interaction in Insertion Section of SSMB Storage Ring Based on Transverse-Longitudinal Coupling Scheme	147
	C.-Y. Tsai HUST, Wuhan, People’s Republic of China X.J. Deng TUB, Beijing, People’s Republic of China
	Funding: This work is supported by the Fundamental Research Funds for the Central Universities (HUST) under Project No. 2021GCRC006 and National Natural Science Foundation of China under project No. 12275094. Recently a mechanism of the steady-state microbunching (SSMB) in a storage ring has been proposed and investigated. The SSMB aims to maintain the same excellent high repetition rate, close to continuous-wave operation, as the storage ring. Moreover, replacing the conventional RF cavity with a laser modulator for longitudinal focusing, the individual electron bunches can be microbunched in a steady state. The microbunched electron bunch train, with individual bunch length comparable to or shorter than the radiation wavelength, can not only produce coherent powerful synchrotron radiations but may also be subject to FEL-like collective instabilities. Our previous analysis was based on the wake-impedance model. In this paper, we have developed a recursive model for the laser modulator in the SSMB storage ring. In particular, the transverse-longitudinal coupling scheme is assumed. Equipped with the above matrix formalism, we can construct a recursive model to account for turn-by-turn evolution, including single-particle and second moments. It is possible to obtain a simplified analytical expression to identify the stability regime or tolerance range for non-perfect cancellation. C.-Y. Tsai, PRAB 25, 064401 (2022). C.-Y. Tsai, NIMA 1042 (2022) 167454. **X.J. Deng et al., NIMA 1019 (2021) 165859.
DOI •	reference for this paper ※ doi:10.18429/JACoW-FLS2023-TU4P31
About •	Received ※ 23 August 2023 — Revised ※ 24 August 2023 — Accepted ※ 30 August 2023 — Issued ※ 02 December 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

TU1B2

Low-alpha Storage Ring Design for Steady-State Microbunching to Generate EUV Radiation

Z. Pan, A. Chao, X.J. Deng, W.-H. Huang, R.K. Li, Z.Z. Li, C.-X. Tang
TUB, Beijing, People’s Republic of China

A new concept is proposed for minimizing the longitudinal emittance of a low momentum compaction factor (low-alpha) storage ring which has the capability to stably store sub-femtosecond electron bunches for the first time. This storage ring is designed for Steady-State microbunching (SSMB) to generate kW level average power EUV radiation. The proposed design approach can be applied to any quasi-isochronous storage rings to yield very high radiation power due to longitudinal coherence of the radiation. We obtain an optimal lattice design by minimizing global and local momentum compaction factors simultaneously and the result of single-particle tracking shows that the electron beam with equilibrium rms bunch length of about 40 nm can be stored in this ring. We also clarify in this type ring, the horizontal emittance will be fixed when beam energy, dipole bending angle and cell tune is fixed. In this type ring, the calculation for IBS effect will be different with traditional rings, we point out where the difference is and give a more convenient calculation for it.

Slides TU1B2 [1.628 MB]

Cite •

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

TU4P28

Useful Formulas and Example Parameters Set for the Design of SSMB Storage Rings

135

X.J. Deng, A. Chao, W.-H. Huang, Z.Z. Li, Z. Pan, C.-X. Tang
TUB, Beijing, People’s Republic of China

A promising accelerator light source mechanism called steady-state microbunching (SSMB) has been actively studied in recent years. Here we summarize some important formulas for the design of SSMB storage rings. Generally we group our formulas into two categories, i.e., a longitudinal weak focusing storage ring for a desired radiation wavelength larger than 100 nm, and a transverse-longitudinal coupling, or a generalized longitudinal strong focusing, storage ring for a desired radiation wavelength between 1 nm and 100 nm. In each category, we have presented an example parameters set for the corresponding SSMB storage ring, to generate kW-level infrared, EUV and soft X-ray radiation, respectively.

DOI •

reference for this paper ※ doi:10.18429/JACoW-FLS2023-TU4P28

About •

Received ※ 15 August 2023 — Revised ※ 24 August 2023 — Accepted ※ 30 August 2023 — Issued ※ 02 December 2023

Cite •

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

TU4P29

Why is the Coherent Radiation from Laser-induced Microbunches Narrowbanded and Collimated

139

X.J. Deng, A. Chao
TUB, Beijing, People’s Republic of China

There are two reasons: one is the long coherence length of radiation from micobunches imprinted by the modulation laser, the second is the finite transverse electron beam size. In other words, one is due to the longitudinal form factor, and the other the transverse form factor of the electron beam. Here we study the role of these form factors in shaping the energy spectrum and spatial distribution of microbunching radiation. The investigations are of value for cases like steady-state microbunching (SSMB), coherent harmonic generation (CHG) and free-electron laser (FEL).

DOI •

reference for this paper ※ doi:10.18429/JACoW-FLS2023-TU4P29

About •

Received ※ 14 August 2023 — Revised ※ 24 August 2023 — Accepted ※ 30 August 2023 — Issued ※ 02 December 2023

Cite •

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

TU4P30

Optical Stochastic Cooling in a General Coupled Lattice

143

X.J. Deng
TUB, Beijing, People’s Republic of China

Here we present a formalism of optical stochastic cooling in a 3D general coupled lattice. The formalism is general, and can treat a variety of damping and diffusion mechanisms within a single framework. We expect the work to be of value for the development of future light source.

DOI •

reference for this paper ※ doi:10.18429/JACoW-FLS2023-TU4P30

About •

Received ※ 15 August 2023 — Revised ※ 24 August 2023 — Accepted ※ 30 August 2023 — Issued ※ 02 December 2023

Cite •

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

TU4P31

A Recursive Model for Laser-Electron-Radiation Interaction in Insertion Section of SSMB Storage Ring Based on Transverse-Longitudinal Coupling Scheme

147

C.-Y. Tsai
HUST, Wuhan, People’s Republic of China
X.J. Deng
TUB, Beijing, People’s Republic of China

Funding: This work is supported by the Fundamental Research Funds for the Central Universities (HUST) under Project No. 2021GCRC006 and National Natural Science Foundation of China under project No. 12275094.
Recently a mechanism of the steady-state microbunching (SSMB) in a storage ring has been proposed and investigated. The SSMB aims to maintain the same excellent high repetition rate, close to continuous-wave operation, as the storage ring. Moreover, replacing the conventional RF cavity with a laser modulator for longitudinal focusing, the individual electron bunches can be microbunched in a steady state. The microbunched electron bunch train, with individual bunch length comparable to or shorter than the radiation wavelength, can not only produce coherent powerful synchrotron radiations but may also be subject to FEL-like collective instabilities. Our previous analysis was based on the wake-impedance model*. In this paper, we have developed a recursive model for the laser modulator in the SSMB storage ring. In particular, the transverse-longitudinal coupling scheme is assumed**. Equipped with the above matrix formalism, we can construct a recursive model to account for turn-by-turn evolution, including single-particle and second moments. It is possible to obtain a simplified analytical expression to identify the stability regime or tolerance range for non-perfect cancellation.
*C.-Y. Tsai, PRAB 25, 064401 (2022). C.-Y. Tsai, NIMA 1042 (2022) 167454.
**X.J. Deng et al., NIMA 1019 (2021) 165859.

DOI •

reference for this paper ※ doi:10.18429/JACoW-FLS2023-TU4P31

About •

Received ※ 23 August 2023 — Revised ※ 24 August 2023 — Accepted ※ 30 August 2023 — Issued ※ 02 December 2023

Cite •

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