SAP2023 - List of Authors (Lin, C.T.)

Paper	Title	Page
MOCXA02	Beam-Beam Interaction with Longitudinal Impedance and Its Application in TMCI Study	1
	C.T. Lin IASF, Shenzhen, Guangdong, People’s Republic of China K. Ohmi KEK, Ibaraki, Japan Y. Zhang IHEP, Beijing, People’s Republic of China
	Simulations have showed a novel coherent head-tail instability induced by beam-beam interaction with a large Piwinski angle. The localized cross-wake force has been introduced to explain the instability. The longitudinal impedance would cause coherent and incoherent synchrotron tune shift and distort the particle¿s trajectories in longitudinal phase space. Further beam-beam simulation revealed that the longitudinal impedance has strong impacts on the beam stability, squeezing the horizontal stable tune area seriously. The instability has become an important issue during the designs of CEPC and FCC-ee. In this paper, we develop a transverse mode coupling analysis method that could be used to study beam-beam instability with and without longitudinal impedance. This method can also be applied in synchrotron light sources to study transverse mode coupling instability (TMCI) with longitudinal impedance and harmonic cavity. Some preliminary results at Shenzhen Innovation Light Source (SILF) are also shown.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOCXA02
About •	Received ※ 30 June 2023 — Accepted ※ 11 July 2023 — Issued ※ 23 September 2024
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPB014	Development of a Vlasov Solver for Arbitrary Sub-optimal Lengthening Conditions in Double-RF System	34
	J.Y. Xu, N. Wang, H.S. Xu, Y. Zhang IHEP, Beijing, People’s Republic of China C.T. Lin IASF, Shenzhen, Guangdong, People’s Republic of China
	Solving Vlasov equation is a classic method for analyzing collective beam instabilities. Considering longitudinal impedance and the nonlinear longitudinal potential well, we developed a new Vlasov solver which can be used to study the transverse mode-coupling instability under the arbitrary sub-optimal lengthening and the optimal lengthening conditions in a double-RF system. Several different techniques to deal with the radial direction of longitudinal phase space have been tested. Numerical discretization method is selected in this paper. The development of the solver is presented in details here. Benchmarks and crosscheck of the solver have been made and presented as well.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB014
About •	Received ※ 30 June 2023 — Revised ※ 08 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 21 August 2024
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Beam-Beam Interaction with Longitudinal Impedance and Its Application in TMCI Study

1

C.T. Lin
IASF, Shenzhen, Guangdong, People’s Republic of China
K. Ohmi
KEK, Ibaraki, Japan
Y. Zhang
IHEP, Beijing, People’s Republic of China

Simulations have showed a novel coherent head-tail instability induced by beam-beam interaction with a large Piwinski angle. The localized cross-wake force has been introduced to explain the instability. The longitudinal impedance would cause coherent and incoherent synchrotron tune shift and distort the particle¿s trajectories in longitudinal phase space. Further beam-beam simulation revealed that the longitudinal impedance has strong impacts on the beam stability, squeezing the horizontal stable tune area seriously. The instability has become an important issue during the designs of CEPC and FCC-ee. In this paper, we develop a transverse mode coupling analysis method that could be used to study beam-beam instability with and without longitudinal impedance. This method can also be applied in synchrotron light sources to study transverse mode coupling instability (TMCI) with longitudinal impedance and harmonic cavity. Some preliminary results at Shenzhen Innovation Light Source (SILF) are also shown.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOCXA02

About •

Received ※ 30 June 2023 — Accepted ※ 11 July 2023 — Issued ※ 23 September 2024

Cite •

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

MOPB014

Development of a Vlasov Solver for Arbitrary Sub-optimal Lengthening Conditions in Double-RF System

34

J.Y. Xu, N. Wang, H.S. Xu, Y. Zhang
IHEP, Beijing, People’s Republic of China
C.T. Lin
IASF, Shenzhen, Guangdong, People’s Republic of China

Solving Vlasov equation is a classic method for analyzing collective beam instabilities. Considering longitudinal impedance and the nonlinear longitudinal potential well, we developed a new Vlasov solver which can be used to study the transverse mode-coupling instability under the arbitrary sub-optimal lengthening and the optimal lengthening conditions in a double-RF system. Several different techniques to deal with the radial direction of longitudinal phase space have been tested. Numerical discretization method is selected in this paper. The development of the solver is presented in details here. Benchmarks and crosscheck of the solver have been made and presented as well.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB014

About •

Received ※ 30 June 2023 — Revised ※ 08 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 21 August 2024

Cite •

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