IPAC2018 - List of Authors (Tanaka, H.)

Paper	Title	Page
WEXGBD2	Pulse-by-Pulse Multi-XFEL Beamline Operation with Ultra-Short Laser Pulses	1740
	T. Hara, T. Inagaki, H. Maesaka, Y. Otake, H. Tanaka, K. Togawa RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan K. Fukami JASRI/SPring-8, Hyogo-ken, Japan T. Hasegawa, O. Morimoto, S. Nakazawa, M. Yoshioka SES, Hyogo-pref., Japan H. Kawaguchi, Y. Kawaguchi Nichicon (Kusatsu) Corporation, Shiga, Japan C. Kondo JASRI, Hyogo, Japan
	The parallel operation of multiple beamlines is an important issue to expand the opportunity of user experiments for linac based FELs. At SACLA, the parallel operation of three beamlines, BL1~3, has been open to user experiments since September 2017. BL1 is a soft x-ray beamline driven by a dedicated accelerator, which is a former SCSS linac, and BL2 and 3 are XFEL beamlines, which share the electron beam from the SACLA main linac. In the parallel operation, a kicker magnet with 10 ppm stability (peak-to-peak) switches the two XFEL beamlines at 60 Hz from pulse to pulse. To ensure wide spectral tunability and optimize the laser performance, the energies and lengths of the electron bunches are independently adjusted for the two beamlines according to user experiments. Since the electron bunch of SACLA has typically 10~15 fs (FWHM) in length and its peak current exceeds 10 kA, the CSR effect at a dogleg beam transport to BL2 is quite significant. In order to suppress the CSR effects, an isochronous and achromatic lattice based on two DBA structures was introduced. In this talk, the multiple XFEL beamline operation and achieved laser performance are presented.
	Slides WEXGBD2 [9.708 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEXGBD2
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WEYGBF4	Development of a Solid-State Pulse Generator Driving Kicker Magnets for a Novel Injection System of a Low Emittance Storage Ring	1804
	T. Inagaki, H. Tanaka RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan H. Akikawa, K. Sato Nihon Koshuha Co. Ltd, Yokohama, Japan K. Fukami, C. Kondo, S. Takano Japan Synchrotron Radiation Research Institute (JASRI), RIKEN SPring-8 Center, Hyogo, Japan
	Funding: Funded by MEXT Japan A next generation electron storage ring represented by a diffraction-limited light source pursues an extremely low emittance leading to a small dynamic aperture and short beam lifetime. The top-up injection is hence indispensable to keep the stored beam current. The beam orbit fluctuation caused by the injection magnets should seriously obstruct utilization of an electron beam with sharp transverse profile. In order to solve these problems, a novel off-axis in-vacuum beam injection system was proposed. In the system, twin kicker magnets driven by a single solid-state pulsed power supply to launch a linear pi- bump orbit is the key to suppress the horizontal orbit fluctuation down to a level of several microns. Here, a big challenge is to achieve the magnetic field identity of the two kickers within an accuracy of 0.1%. This presentation overviews the proposed injection system and reports the development status focusing on the solid-state pulse generator.
	Slides WEYGBF4 [3.062 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEYGBF4
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THPMF059	Simulation Studies of Beam Commissioning and Expected Performance of the SPring-8-II Storage Ring	4203
	Y. Shimosaki JASRI, Hyogo, Japan K. Soutome, M. Takao JASRI/SPring-8, Hyogo-ken, Japan H. Tanaka RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
	In the SPring-8 upgrade project, the 5-bend achromat lattice is adopted for achieving a very low emittance of 157 pm.rad at 6 GeV. Since the dynamic aperture (DA) and the beam performance become sensitive against errors due to the strong quadrupoles and sextupoles, we carried out tracking simulations to evaluate the tolerance of machine imperfections such as the misalignment, magnetic field errors, the BPM offset, etc. It is found that the first-turn-steering (FTS) with the use of single-pass BPM's is indispensable because even under strict (but attainable) tolerances the beam cannot be stored without steering kicks. We then confirmed that after the FTS a sufficiently large DA can be obtained for accumulating the beam by the off-axis injection. By performing the orbit and optics corrections for the stored beam, we can finally achieve an emittance value of 160 ~ 180 pm.rad, being close to the design value. We also found that a naive application of the SVD algorithm to orbit corrections yields unwanted local bumps between BPM's and this deteriorates the vertical emittance. A possible scheme to avoid such local bumps by effectively interpolating the measured orbit will be discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF059
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THPMF060	Touschek Beam Loss Simulation for Light Source Storage Rings	4206
	M. Takao, K. Soutome JASRI/SPring-8, Hyogo-ken, Japan Y. Shimosaki JASRI, Hyogo, Japan K. Soutome, H. Tanaka RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
	In light source storage rings, it is important to know the distribution of lost electrons due to the Touschek scattering for protecting insertion devices (IDs) from radiation damage. This will become crucial especially in future light sources where narrow gap in-vacuum IDs are normally used. While the Touschek scattered electron begins to oscillate in the horizontal direction with the amplitude proportional to the dispersion at the scattering point and to the momentum deviation after scattering, the motion is converted into the vertical direction due to the betatron coupling and some of the scattered electrons are lost at the narrow gaps of in-vacuum IDs. The momentum deviation by the Touschek scattering reaches 5% more, and according to which the vertical oscillation is more excited. Hence electrons even scattered at small horizontal dispersion are also lost at narrow gap IDs. We carried out computer simulations by taking the present SPring-8 storage ring and a planned 3GeV low-emittance ring as examples. The results and possible measures for ID protection will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF060
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THPMF061	Updates on Hardware Developments for SPring-8-II	4209
	T. Watanabe, S. Takano Japan Synchrotron Radiation Research Institute (JASRI), RIKEN SPring-8 Center, Hyogo, Japan H. Tanaka RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
	We will report the updates on hardware developments for SPring-8-II including a status on a test half-cell construction. A major upgrade of SPring-8, SPring-8-II, targeting substantial improvements in the light source performance is based on a five-bend achromat lattice at an electron energy of 6 GeV, and hardware accommodating with the new lattice have been extensively developed. Some of key features are permanent dipole magnets, SUS vacuum chambers, highly accurate and reliable electron and photon beam position monitors, and an extremely small emittance beam injection from the SACLA linac to the storage ring. In the process of the optimization, we cannot rely merely on independent developments; the high packing factor lattice naturally imposes an integration of the individual efforts into a whole design. Thus, a test-half cell has been constructed as one of important milestones, where we need to carefully look through specification balances between different components, physical and magnetic interferences, etc. The presentation will give overall status on the developments as well as the test half-cell construction. H. Tanaka et al., Proc. of IPAC2016, Busan, Korea (2016), p.2867. K. Soutome and H. Tanaka, PRAB 20, 064001 (2017). ** e,g, T. Watanabe et al., PRAB 20, 072401 (2017).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF061
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Paper

Title

Page

Pulse-by-Pulse Multi-XFEL Beamline Operation with Ultra-Short Laser Pulses

1740

T. Hara, T. Inagaki, H. Maesaka, Y. Otake, H. Tanaka, K. Togawa
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
K. Fukami
JASRI/SPring-8, Hyogo-ken, Japan
T. Hasegawa, O. Morimoto, S. Nakazawa, M. Yoshioka
SES, Hyogo-pref., Japan
H. Kawaguchi, Y. Kawaguchi
Nichicon (Kusatsu) Corporation, Shiga, Japan
C. Kondo
JASRI, Hyogo, Japan

The parallel operation of multiple beamlines is an important issue to expand the opportunity of user experiments for linac based FELs. At SACLA, the parallel operation of three beamlines, BL1~3, has been open to user experiments since September 2017. BL1 is a soft x-ray beamline driven by a dedicated accelerator, which is a former SCSS linac, and BL2 and 3 are XFEL beamlines, which share the electron beam from the SACLA main linac. In the parallel operation, a kicker magnet with 10 ppm stability (peak-to-peak) switches the two XFEL beamlines at 60 Hz from pulse to pulse. To ensure wide spectral tunability and optimize the laser performance, the energies and lengths of the electron bunches are independently adjusted for the two beamlines according to user experiments. Since the electron bunch of SACLA has typically 10~15 fs (FWHM) in length and its peak current exceeds 10 kA, the CSR effect at a dogleg beam transport to BL2 is quite significant. In order to suppress the CSR effects, an isochronous and achromatic lattice based on two DBA structures was introduced. In this talk, the multiple XFEL beamline operation and achieved laser performance are presented.

Slides WEXGBD2 [9.708 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEXGBD2

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WEYGBF4

Development of a Solid-State Pulse Generator Driving Kicker Magnets for a Novel Injection System of a Low Emittance Storage Ring

1804

T. Inagaki, H. Tanaka
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
H. Akikawa, K. Sato
Nihon Koshuha Co. Ltd, Yokohama, Japan
K. Fukami, C. Kondo, S. Takano
Japan Synchrotron Radiation Research Institute (JASRI), RIKEN SPring-8 Center, Hyogo, Japan

Funding: Funded by MEXT Japan
A next generation electron storage ring represented by a diffraction-limited light source pursues an extremely low emittance leading to a small dynamic aperture and short beam lifetime. The top-up injection is hence indispensable to keep the stored beam current. The beam orbit fluctuation caused by the injection magnets should seriously obstruct utilization of an electron beam with sharp transverse profile. In order to solve these problems, a novel off-axis in-vacuum beam injection system was proposed. In the system, twin kicker magnets driven by a single solid-state pulsed power supply to launch a linear pi- bump orbit is the key to suppress the horizontal orbit fluctuation down to a level of several microns. Here, a big challenge is to achieve the magnetic field identity of the two kickers within an accuracy of 0.1%. This presentation overviews the proposed injection system and reports the development status focusing on the solid-state pulse generator.

Slides WEYGBF4 [3.062 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEYGBF4

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THPMF059

Simulation Studies of Beam Commissioning and Expected Performance of the SPring-8-II Storage Ring

4203

Y. Shimosaki
JASRI, Hyogo, Japan
K. Soutome, M. Takao
JASRI/SPring-8, Hyogo-ken, Japan
H. Tanaka
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

In the SPring-8 upgrade project, the 5-bend achromat lattice is adopted for achieving a very low emittance of 157 pm.rad at 6 GeV. Since the dynamic aperture (DA) and the beam performance become sensitive against errors due to the strong quadrupoles and sextupoles, we carried out tracking simulations to evaluate the tolerance of machine imperfections such as the misalignment, magnetic field errors, the BPM offset, etc. It is found that the first-turn-steering (FTS) with the use of single-pass BPM's is indispensable because even under strict (but attainable) tolerances the beam cannot be stored without steering kicks. We then confirmed that after the FTS a sufficiently large DA can be obtained for accumulating the beam by the off-axis injection. By performing the orbit and optics corrections for the stored beam, we can finally achieve an emittance value of 160 ~ 180 pm.rad, being close to the design value. We also found that a naive application of the SVD algorithm to orbit corrections yields unwanted local bumps between BPM's and this deteriorates the vertical emittance. A possible scheme to avoid such local bumps by effectively interpolating the measured orbit will be discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF059

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THPMF060

Touschek Beam Loss Simulation for Light Source Storage Rings

4206

M. Takao, K. Soutome
JASRI/SPring-8, Hyogo-ken, Japan
Y. Shimosaki
JASRI, Hyogo, Japan
K. Soutome, H. Tanaka
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

In light source storage rings, it is important to know the distribution of lost electrons due to the Touschek scattering for protecting insertion devices (IDs) from radiation damage. This will become crucial especially in future light sources where narrow gap in-vacuum IDs are normally used. While the Touschek scattered electron begins to oscillate in the horizontal direction with the amplitude proportional to the dispersion at the scattering point and to the momentum deviation after scattering, the motion is converted into the vertical direction due to the betatron coupling and some of the scattered electrons are lost at the narrow gaps of in-vacuum IDs. The momentum deviation by the Touschek scattering reaches 5% more, and according to which the vertical oscillation is more excited. Hence electrons even scattered at small horizontal dispersion are also lost at narrow gap IDs. We carried out computer simulations by taking the present SPring-8 storage ring and a planned 3GeV low-emittance ring as examples. The results and possible measures for ID protection will be presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF060

Export •

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

THPMF061

Updates on Hardware Developments for SPring-8-II

4209

T. Watanabe, S. Takano
Japan Synchrotron Radiation Research Institute (JASRI), RIKEN SPring-8 Center, Hyogo, Japan
H. Tanaka
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

We will report the updates on hardware developments for SPring-8-II including a status on a test half-cell construction. A major upgrade of SPring-8, SPring-8-II, targeting substantial improvements in the light source performance is based on a five-bend achromat lattice at an electron energy of 6 GeV*, and hardware accommodating with the new lattice have been extensively developed**. Some of key features are permanent dipole magnets, SUS vacuum chambers, highly accurate and reliable electron and photon beam position monitors, and an extremely small emittance beam injection from the SACLA linac to the storage ring. In the process of the optimization, we cannot rely merely on independent developments; the high packing factor lattice naturally imposes an integration of the individual efforts into a whole design. Thus, a test-half cell has been constructed as one of important milestones, where we need to carefully look through specification balances between different components, physical and magnetic interferences, etc. The presentation will give overall status on the developments as well as the test half-cell construction.
* H. Tanaka et al., Proc. of IPAC2016, Busan, Korea (2016), p.2867. K. Soutome and H. Tanaka, PRAB 20, 064001 (2017).
** e,g, T. Watanabe et al., PRAB 20, 072401 (2017).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF061

Export •

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