IPAC2018 - List of Authors (Bai, Z.H.)

Paper	Title	Page
THPAK147	Super-Period Multi-Bend Achromat Lattice with Interleaved Dispersion Bumps for the HALS Storage Ring	3597
	Z.H. Bai, L. Wang USTC/NSRL, Hefei, Anhui, People's Republic of China
	We have proposed a multi-bend achromat (MBA) lattice concept, called the MBA with interleaved dispersion bumps, in which two pairs of interleaved dispersion bumps are created in each lattice cell. Due to that many nonlinear effects can be effectively cancelled out within one cell and also many knobs can be used for nonlinear optimization, this MBA concept has given both large dynamic aperture (DA) and large dynamic momentum aperture in the lattice design of the Hefei Advanced Light Source (HALS). In this paper, to further enlarge DA, we extend the concept to the case of a super-period lattice consisting of two cells. In the super-period lattice, there are 1.5 pairs of bumps in each cell. A super-period 7BA lattice is preliminarily designed for the HALS, and a larger DA is obtained.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK147
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THPAK148	Preliminary Study of a Nine-Bend Achromat Lattice for a Diffraction-Limited Storage Ring	3600
	P.H. Yang, Z.H. Bai, L. Wang USTC/NSRL, Hefei, Anhui, People's Republic of China
	In recent years, multi-bend achromat (MBA) lattices have been widely used for the design of diffraction-limited storage rings (DLSRs) being developed around the world as the next-generation storage ring synchrotron sources. To better solve the problem of very serious non-linear dynamics in the DLSR lattice design, recently we proposed a new MBA lattice concept called the MBA lattice with interleaved dispersion bumps , which was then applied to designing 7BA lattices for the Hefei Ad-vanced Light Source (HALS), with the result showing rather good nonlinear dynamics performance. In this paper, a 9BA lattice also following our MBA concept is preliminarily designed as a possible option for the HALS with a natural emittance of less than 30 pm·rad. Since generally the 9BA lattice can have a much lower emit-tance than the usually used 7BA lattice, the work in the paper will provide an inspiration for the existing third-generation synchrotron sources to upgrade to DLSRs with much lower emittances. Zhenghe Bai et al., MOPH13, Proc. SAP2017, Jishou, China, 2017.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK148
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THPAK152	Study of GF Symplectic Tracking Method and Compensation for the EPU10⁴ at the HLS-II	3603
	Z.H. Yang, Z.H. Bai, W. Li, G. Liu, L. Wang USTC/NSRL, Hefei, Anhui, People's Republic of China
	An elliptically polarized undulator (EPU) was applied to obtain high-brightness coherent synchrotron radiation at the upgraded Hefei Light Source, HLS-II. However, the EPU has serious dynamic effects on the beam performances including close orbit, emittance and dynamic aperture etc. when installed at the storage ring. In order to understand the effects, a Taylor expanded generating method was adopted to generate a fast and symplectic map for particle tracking. As for the compensation of the EPU, striplines were equipped above and below the vacuum chamber to reduce the nonlinear effects. With the symplectic tracking routine and the surface fitting method, different parameters such as dynamic aperture and the driving terms, could be set as the objective function to accomplish the optimization of the EPU.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK152
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THPMK120	Hefei Advanced Light Source: A Future Soft X-Ray Diffraction-Limited Storage Ring at NSRL	4598
	L. Wang, Z.H. Bai, N. Hu, H.T. Li, W. Li, G. Liu, Y. Lu, Q. Luo, D.R. Xu, W. Xu, P.H. Yang, Z.H. Yang, S.C. Zhang USTC/NSRL, Hefei, Anhui, People's Republic of China
	To meet the fast-growing demands for high-quality low-energy photon beams, a new synchrotron radiation light source conception was brought forward several years ago by National Synchrotron Radiation Laboratory, which was named Hefei Advanced Light Source (HALS). The dominant radiation of HALS will be located in the VUV and soft X-ray region, which will be complementary with that of SSRF and HEPS. Except for high brilliance, high transverse coherence will be another signature feature of HALS. To achieve these goals, a multi-bend achromat based diffraction-limited storage ring was adopted as the main body of HALS. The general description and preliminary design of HALS will be briefly presented in this paper. Under the support of the Chinese Academy of Sciences and local government, the preliminary research and development (R&D) for HALS is undergoing. Several key technologies will be developed in the R&D project, which will lay good foundation for the construction of HALS.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK120
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THPMK121	Design of the Second Version of the HALS Storage Ring Lattice	4601
	Z.H. Bai, W. Li, L. Wang, P.H. Yang, Z.H. Yang USTC/NSRL, Hefei, Anhui, People's Republic of China
	In this paper, a new multi-bend achromat (MBA) lat-tice concept that we recently proposed for diffraction-limited storage rings is described, where two pairs of interleaved dispersion bumps are created in each cell and also most of the nonlinear effects produced by the sextupoles located in these bumps can be cancelled out within one cell. Following this concept, two 7BA lattices have been designed for the Hefei Advanced Light Source storage ring as the second version lattic-es, one with uniform dipoles and the other with nonu-niform dipoles. The latter has a lower natural emit-tance of 23 pm·rad, in which longitudinal gradient bends and anti-bends are employed. The optimized nonlinear dynamics for these two lattices are rather good, and especially the dynamic momentum aperture can be larger than 8% without off-momentum tunes crossing non-structure half-integer resonance lines.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK121
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THPMK135	Corrector Layout Optimization Using NSGA-II for HALS	4629
	D.R. Xu, Z.H. Bai, L. Wang, W. Wang, H. Xu USTC/NSRL, Hefei, Anhui, People's Republic of China
	In this paper, we present a method to find the global optimum correctors layout based NSGA-II algorithm when the number of correctors is limited to be equal to the number of BPMs. We prove that this method works well with HALS.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK135
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Paper

Title

Page

Super-Period Multi-Bend Achromat Lattice with Interleaved Dispersion Bumps for the HALS Storage Ring

3597

Z.H. Bai, L. Wang
USTC/NSRL, Hefei, Anhui, People's Republic of China

We have proposed a multi-bend achromat (MBA) lattice concept, called the MBA with interleaved dispersion bumps, in which two pairs of interleaved dispersion bumps are created in each lattice cell. Due to that many nonlinear effects can be effectively cancelled out within one cell and also many knobs can be used for nonlinear optimization, this MBA concept has given both large dynamic aperture (DA) and large dynamic momentum aperture in the lattice design of the Hefei Advanced Light Source (HALS). In this paper, to further enlarge DA, we extend the concept to the case of a super-period lattice consisting of two cells. In the super-period lattice, there are 1.5 pairs of bumps in each cell. A super-period 7BA lattice is preliminarily designed for the HALS, and a larger DA is obtained.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK147

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THPAK148

Preliminary Study of a Nine-Bend Achromat Lattice for a Diffraction-Limited Storage Ring

3600

P.H. Yang, Z.H. Bai, L. Wang
USTC/NSRL, Hefei, Anhui, People's Republic of China

In recent years, multi-bend achromat (MBA) lattices have been widely used for the design of diffraction-limited storage rings (DLSRs) being developed around the world as the next-generation storage ring synchrotron sources. To better solve the problem of very serious non-linear dynamics in the DLSR lattice design, recently we proposed a new MBA lattice concept called the MBA lattice with interleaved dispersion bumps *, which was then applied to designing 7BA lattices for the Hefei Ad-vanced Light Source (HALS), with the result showing rather good nonlinear dynamics performance. In this paper, a 9BA lattice also following our MBA concept is preliminarily designed as a possible option for the HALS with a natural emittance of less than 30 pm·rad. Since generally the 9BA lattice can have a much lower emit-tance than the usually used 7BA lattice, the work in the paper will provide an inspiration for the existing third-generation synchrotron sources to upgrade to DLSRs with much lower emittances.
* Zhenghe Bai et al., MOPH13, Proc. SAP2017, Jishou, China, 2017.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK148

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THPAK152

Study of GF Symplectic Tracking Method and Compensation for the EPU10⁴ at the HLS-II

3603

Z.H. Yang, Z.H. Bai, W. Li, G. Liu, L. Wang
USTC/NSRL, Hefei, Anhui, People's Republic of China

An elliptically polarized undulator (EPU) was applied to obtain high-brightness coherent synchrotron radiation at the upgraded Hefei Light Source, HLS-II. However, the EPU has serious dynamic effects on the beam performances including close orbit, emittance and dynamic aperture etc. when installed at the storage ring. In order to understand the effects, a Taylor expanded generating method was adopted to generate a fast and symplectic map for particle tracking. As for the compensation of the EPU, striplines were equipped above and below the vacuum chamber to reduce the nonlinear effects. With the symplectic tracking routine and the surface fitting method, different parameters such as dynamic aperture and the driving terms, could be set as the objective function to accomplish the optimization of the EPU.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK152

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THPMK120

Hefei Advanced Light Source: A Future Soft X-Ray Diffraction-Limited Storage Ring at NSRL

4598

L. Wang, Z.H. Bai, N. Hu, H.T. Li, W. Li, G. Liu, Y. Lu, Q. Luo, D.R. Xu, W. Xu, P.H. Yang, Z.H. Yang, S.C. Zhang
USTC/NSRL, Hefei, Anhui, People's Republic of China

To meet the fast-growing demands for high-quality low-energy photon beams, a new synchrotron radiation light source conception was brought forward several years ago by National Synchrotron Radiation Laboratory, which was named Hefei Advanced Light Source (HALS). The dominant radiation of HALS will be located in the VUV and soft X-ray region, which will be complementary with that of SSRF and HEPS. Except for high brilliance, high transverse coherence will be another signature feature of HALS. To achieve these goals, a multi-bend achromat based diffraction-limited storage ring was adopted as the main body of HALS. The general description and preliminary design of HALS will be briefly presented in this paper. Under the support of the Chinese Academy of Sciences and local government, the preliminary research and development (R&D) for HALS is undergoing. Several key technologies will be developed in the R&D project, which will lay good foundation for the construction of HALS.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK120

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THPMK121

Design of the Second Version of the HALS Storage Ring Lattice

4601

Z.H. Bai, W. Li, L. Wang, P.H. Yang, Z.H. Yang
USTC/NSRL, Hefei, Anhui, People's Republic of China

In this paper, a new multi-bend achromat (MBA) lat-tice concept that we recently proposed for diffraction-limited storage rings is described, where two pairs of interleaved dispersion bumps are created in each cell and also most of the nonlinear effects produced by the sextupoles located in these bumps can be cancelled out within one cell. Following this concept, two 7BA lattices have been designed for the Hefei Advanced Light Source storage ring as the second version lattic-es, one with uniform dipoles and the other with nonu-niform dipoles. The latter has a lower natural emit-tance of 23 pm·rad, in which longitudinal gradient bends and anti-bends are employed. The optimized nonlinear dynamics for these two lattices are rather good, and especially the dynamic momentum aperture can be larger than 8% without off-momentum tunes crossing non-structure half-integer resonance lines.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK121

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

THPMK135

Corrector Layout Optimization Using NSGA-II for HALS

4629

D.R. Xu, Z.H. Bai, L. Wang, W. Wang, H. Xu
USTC/NSRL, Hefei, Anhui, People's Republic of China

In this paper, we present a method to find the global optimum correctors layout based NSGA-II algorithm when the number of correctors is limited to be equal to the number of BPMs. We prove that this method works well with HALS.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK135

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