NAPAC2016 - List of Authors (Xiao, A.)

Paper	Title	Page
WEPOB10	Simulation Study of the Helical Superconducting Undulator Installation at the Advanced Photon Source	907
	V. Sajaev, M. Borland, Y.P. Sun, A. Xiao ANL, Argonne, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. A helical superconducting undulator is planned for installation at the APS. Such an installation would be first of its kind – helical devices were never installed in synchrotron light sources before. Due to its reduced horizontal aperture, a lattice modification is required to accommodate for large horizontal oscillations during injection. We describe the lattice change details and show the new lattice experimental test results. To understand the effect of the undulator on single-particle dynamics, first, its kick maps were computed using different methods. We have found that often-used Elleaume formula* for kick maps gives wrong results for this undulator. We then used the kick maps obtained by other methods to simulate the effect of the undulator on injection and lifetime. *P. Elleaume, EPAC 1992
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB10
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WEPOB21	Benchmarking of Touschek Beam Lifetime Calculations for the Advanced Photon Source	940
	A. Xiao, B.X. Yang ANL, Argonne, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. Particle loss from Touschek scattering is one of the most significant issues faced by present and future synchrotron light source storage rings. For example, the predicted, Touschek-dominated beam lifetime for the Advanced Photon Source (APS) Upgrade lattice in 48-bunch, 200-mA timing mode is only ~2 h. In order to understand the reliability of the predicted lifetime, a series of measurements with various beam parameters was performed on the present APS storage ring. This paper first describes the entire process of beam lifetime measurement, then compares measured lifetime with the calculated one by applying the measured beam parameters. The results show very good agreement.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB21
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WEPOB22	Beam Loss Simulation and Collimator System Configurations for the Advanced Photon Source Upgrade	943
	A. Xiao, M. Borland ANL, Argonne, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. The proposed multi-bend achromat lattice for the Advanced Photon Source upgrade (APS-U) has a design emittance of less than 70 pm. The Touschek loss rate is high: compared with the current APS ring, which has an average beam lifetime ∼ 10 h, the simulated beam lifetime for APS-U is only ~2 h when operated in the high flux mode (I=200 mA in 48 bunches). An additional consequence of the short lifetime is that injection must be more frequent, which provides another potential source of particle loss. In order to provide information for the radiation shielding system evaluation and to avoid particle loss in sensitive locations around the ring (for example, insertion device straight sections), simulations of the detailed beam loss distribution have been performed. Several possible collimation configurations have been simulated and compared.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB22
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WEPOB24	Preliminary Test Results of a Prototype Fast Kicker for APS MBA Upgrade	950
	C. Yao, A. Barcikowski, A.R. Brill, J. Carwardine, T.K. Clute, Z.A. Conway, A.R. Cours, G. Decker, R.T. Keane, F. Lenkszus, L.H. Morrison, X. Sun, J. Wang, F. Westferro, A. Xiao ANL, Argonne, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357. The APS multi-bend achromatic (MBA) upgrade storage ring plans to support two bunch fill patterns: a 48-bunch and a 324-bunch. A "swap out" injection scheme is required. In order provide the required kick to injected beam, to minimize the beam loss and residual oscillation of injected beam, and to minimize the perturbation to stored beam during injection, the rise, fall, and flat-top parts of the kicker pulse must be within a 16.9-ns interval. Stripling-type kickers are chosen for both injection and extraction. We developed a prototype kicker that supports a ±15kV differential pulse voltage. We performed high voltage discharge, TDR measurement, high voltage pulse test and beam test of the kicker. We report the design of the fast kicker and the test results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB24
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THPOA63	Septum Magnet Design for APS-U	1231
	M. Abliz, M. Borland, H. Cease, G. Decker, M.S. Jaski, J.S. Kerby, U. Wienands, A. Xiao ANL, Argonne, Illinois, USA
	Funding: * Work supported by the U. S. Department of Energy, Office of Science, under Contract No. DE AC02 06CH11357 The Advanced Photon Source is in the process of developing an upgrade (APS-U) of the storage ring from a double-bend to a multi-bend lattice. A swap-out injection is planned for the APS-U lattice to keep a constant beam current and accommodate small, dynamic aperture. A septum magnet that has a minimum thickness of 2 mm with an injection field of 1.06 T has been designed. The stored beam chamber has an 8 mm x 6 mm super-ellipsoidal aperture. The required total deflecting angle is 89 mrad with a ring energy of 6 GeV. The magnet is straight, but is tilted in yaw, roll, and pitch from the stored beam chamber in order to meet the swap out injection requirements for the APS-U lattice. In order to minimize the leakage field inside the stored beam chamber, four different techniques were utilized in the design. As a result, the horizontal deflecting angle of the stored beam was held to only 5 μrad, and the integrated skew quadrupole inside the stored beam chamber was held to 0.09 T. The detailed techniques that were applied to the design, the field multipoles, and the resulting trajectories of the injected and stored beams are reported.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-THPOA63
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Paper

Title

Page

Simulation Study of the Helical Superconducting Undulator Installation at the Advanced Photon Source

907

V. Sajaev, M. Borland, Y.P. Sun, A. Xiao
ANL, Argonne, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
A helical superconducting undulator is planned for installation at the APS. Such an installation would be first of its kind – helical devices were never installed in synchrotron light sources before. Due to its reduced horizontal aperture, a lattice modification is required to accommodate for large horizontal oscillations during injection. We describe the lattice change details and show the new lattice experimental test results. To understand the effect of the undulator on single-particle dynamics, first, its kick maps were computed using different methods. We have found that often-used Elleaume formula* for kick maps gives wrong results for this undulator. We then used the kick maps obtained by other methods to simulate the effect of the undulator on injection and lifetime.
*P. Elleaume, EPAC 1992

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB10

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WEPOB21

Benchmarking of Touschek Beam Lifetime Calculations for the Advanced Photon Source

940

A. Xiao, B.X. Yang
ANL, Argonne, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
Particle loss from Touschek scattering is one of the most significant issues faced by present and future synchrotron light source storage rings. For example, the predicted, Touschek-dominated beam lifetime for the Advanced Photon Source (APS) Upgrade lattice in 48-bunch, 200-mA timing mode is only ~2 h. In order to understand the reliability of the predicted lifetime, a series of measurements with various beam parameters was performed on the present APS storage ring. This paper first describes the entire process of beam lifetime measurement, then compares measured lifetime with the calculated one by applying the measured beam parameters. The results show very good agreement.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB21

Export •

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

WEPOB22

Beam Loss Simulation and Collimator System Configurations for the Advanced Photon Source Upgrade

943

A. Xiao, M. Borland
ANL, Argonne, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
The proposed multi-bend achromat lattice for the Advanced Photon Source upgrade (APS-U) has a design emittance of less than 70 pm. The Touschek loss rate is high: compared with the current APS ring, which has an average beam lifetime ∼ 10 h, the simulated beam lifetime for APS-U is only ~2 h when operated in the high flux mode (I=200 mA in 48 bunches). An additional consequence of the short lifetime is that injection must be more frequent, which provides another potential source of particle loss. In order to provide information for the radiation shielding system evaluation and to avoid particle loss in sensitive locations around the ring (for example, insertion device straight sections), simulations of the detailed beam loss distribution have been performed. Several possible collimation configurations have been simulated and compared.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB22

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

WEPOB24

Preliminary Test Results of a Prototype Fast Kicker for APS MBA Upgrade

950

C. Yao, A. Barcikowski, A.R. Brill, J. Carwardine, T.K. Clute, Z.A. Conway, A.R. Cours, G. Decker, R.T. Keane, F. Lenkszus, L.H. Morrison, X. Sun, J. Wang, F. Westferro, A. Xiao
ANL, Argonne, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
The APS multi-bend achromatic (MBA) upgrade storage ring plans to support two bunch fill patterns: a 48-bunch and a 324-bunch. A "swap out" injection scheme is required. In order provide the required kick to injected beam, to minimize the beam loss and residual oscillation of injected beam, and to minimize the perturbation to stored beam during injection, the rise, fall, and flat-top parts of the kicker pulse must be within a 16.9-ns interval. Stripling-type kickers are chosen for both injection and extraction. We developed a prototype kicker that supports a ±15kV differential pulse voltage. We performed high voltage discharge, TDR measurement, high voltage pulse test and beam test of the kicker. We report the design of the fast kicker and the test results.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB24

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

THPOA63

Septum Magnet Design for APS-U

1231

M. Abliz, M. Borland, H. Cease, G. Decker, M.S. Jaski, J.S. Kerby, U. Wienands, A. Xiao
ANL, Argonne, Illinois, USA

Funding: * Work supported by the U. S. Department of Energy, Office of Science, under Contract No. DE AC02 06CH11357
The Advanced Photon Source is in the process of developing an upgrade (APS-U) of the storage ring from a double-bend to a multi-bend lattice. A swap-out injection is planned for the APS-U lattice to keep a constant beam current and accommodate small, dynamic aperture. A septum magnet that has a minimum thickness of 2 mm with an injection field of 1.06 T has been designed. The stored beam chamber has an 8 mm x 6 mm super-ellipsoidal aperture. The required total deflecting angle is 89 mrad with a ring energy of 6 GeV. The magnet is straight, but is tilted in yaw, roll, and pitch from the stored beam chamber in order to meet the swap out injection requirements for the APS-U lattice. In order to minimize the leakage field inside the stored beam chamber, four different techniques were utilized in the design. As a result, the horizontal deflecting angle of the stored beam was held to only 5 μrad, and the integrated skew quadrupole inside the stored beam chamber was held to 0.09 T. The detailed techniques that were applied to the design, the field multipoles, and the resulting trajectories of the injected and stored beams are reported.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-THPOA63

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