IPAC2019 - List of Authors (Hara, T.)

Paper	Title	Page
TUPRB042	Design Study of Nonlinear Energy Chirp Correction Using Sextupole Magnets at the Soft X-Ray Free-Electron Laser Beamline of SACLA	1782
	K. Togawa, T. Hara, H. Tanaka RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
	At the x-ray free-electron laser (FEL) facility, SACLA, a soft x-ray FEL beamline (SCSS+) is driven by a dedicated 800-MeV electron accelerator and being operated in parallel with two hard x-ray FEL beamlines. Responding to the demands of short laser pulses from users, a nonlinearity correction system using sextupole magnets is under consideration to obtain shorter electron bunches. Since the frequency of the SCSS+ injector is S-band, the nonlinearity correction of a bunch compression process using a harmonic correction cavity is not so efficient as the SACLA injector, whose frequency of the injector is L-band. Instead of a complex and costly correction cavity system, the sextupole magnets are simply installed in a dispersive section of the first bunch compressor chicane. In this report, we will present the basic design concept and some detail studies of the nonlinear correction.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB042
About •	paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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WEPMP009	Renovation of Off-Axis Beam Injection Scheme for Next-Generation Photon Sources	2318
	S. Takano, K. Fukami, C. Kondo, M. Masaki, M. Oishi, M. Shoji, K. Tamura, T. Taniuchi, T. Watanabe, K. Yanagida JASRI, Hyogo, Japan H. Akikawa, K. Sato Nihon Koshuha Co. Ltd, Yokohama, Japan K. Fukami, T. Hara, T. Inagaki, C. Kondo, M. Oishi, S. Takano, H. Tanaka, T. Watanabe RIKEN SPring-8 Center, Hyogo, Japan K. Hamato, J. Kataoka, K. Kusano, K. Ogata, Y. Saito TOKIN, Sendai, Miyagi, Japan
	Funding: Work supported by Ministry of education, culture, sports, science and technology JAPAN (MEXT). Photon sources are looking for performance upgrades by pursuing higher photon brilliance and coherence these years. The trend is pushing the lattice design to lower the beam emittance, which naturally results in the narrower dynamic aperture. One bottleneck in the upgrades is a beam injection system capable of accumulating required beam intensity and keeping top-up operations with such narrow apertures. Beam injection with a nonlinear kicker and transverse/longitudinal on-axis injections are now in the limelight. However, these techniques still need time to be put into practical use. We take an alternative approach for the SPring-8 upgrade, SPring-8-II, renovating the off-axis beam injection scheme to address the following requirements for the coming diffraction-limited storage rings (DLSRs): minimizing of both injection beam amplitude and perturbation to stored beam, and topping-up functionality. This presentation will overview the renewed off-axis beam injection scheme and report the development status of the following three key components: 1) permanent magnet based DC septum magnet, 2) in-vacuum pulse septum magnet, and 3) twin kickers driven by a single solid state pulser.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP009
About •	paper received ※ 10 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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WEPGW029	The Design of the Control System for the SACLA/SPring-8 Accelerator Complex to Use the LINAC of SACLA for a Full-Energy Injector of SPring-8	2529
	T. Fukui RIKEN SPring-8 Center, Innovative Light Sources Division, Hyogo, Japan T. Hara, N. Hosoda, T. Inagaki, H. Maesaka, T. Ohshima, H. Tanaka RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan T. Hasegawa, O. Morimoto, Y. Tajiri, S. Tanaka, M. Yoshioka SES, Hyogo-pref., Japan S. Matsubara, K. Okada JASRI, Hyogo, Japan M. Yamaga JASRI/SPring-8, Hyogo-ken, Japan
	At the SPring-8 site, the X-ray free electron laser facili-ty, SACLA, and the third-generation light source, SPring-8 storage ring, have been operated. On the SPring-8 up-grade project we have a plan to use the linac of SACLA as a full-energy injector of the storage ring. To achieve the SACLA’s user operation and the beam injection to the storage ring in parallel, it is necessary to control the beam energy and the peak current on a pulse by pulse. The demand for an injection occurs anytime during the top-up operation of the storage ring. For this purpose, two accel-erators should be controlled seamlessly and the SACLA has to provide the low emittance electron beam to gener-ate X-ray laser and to be an injector of the storage ring simultaneously. Because SACLA has to control the beam energy and peak current on a pulse by pulse, we are de-signing a system to meet these requirements. A master controller stores a pattern of parameters required for the low-level RF controllers. Each pattern consists of 60 rows which correspond to the parameters for one second with a beam repetition rate of the SACLA, 60Hz. The master sends the parameters to the controllers with reflective memory. We can select the pattern every second on de-mand and it is flexible enough for the top-up operation of the storage ring. Also the data of low-level RF and beam position monitor are stored into the database with a beam repetition rate. In this paper, we report the design of con-trol system for SACLA/SPring-8 to control the beam energy and the peak current on a pulse by pulse.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW029
About •	paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THYYPLS1	On-Demand Beam Route and RF Parameter Switching System for Time-Sharing of a Linac for X-ray Free-Electron Laser as an Injector to a 4th-Generation Synchrotron Radiation Source	3427
	H. Maesaka, T. Fukui, T. Hara, T. Inagaki, H. Tanaka RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan T. Hasegawa, O. Morimoto, Y. Tajiri, S. Tanaka, M. Yoshioka SES, Hyogo-pref., Japan N. Hosoda, S. Matsubara, T. Ohshima JASRI/SPring-8, Hyogo-ken, Japan C. Kondo, K. Okada, M. Yamaga JASRI, Hyogo, Japan
	We have an upgrade plan of the SPring-8 storage ring to provide much more brilliant X-rays with a low-emittance electron beam. Since the upgraded ring requires a low-emittance injection beam, we are planning to timeshare the linac of the X-ray free electron laser (XFEL) facility, SACLA, as an injector for the upgraded ring. The SACLA linac delivers low-emittance and short-bunch electron beams to two XFEL beamlines with a 60 Hz repetition rate. The beam route is right now equally changed by a kicker magnet at a switchyard. The beam parameter is also optimized for each XFEL beamline by changing RF parameters pulse-by-pulse with simple software at this moment. Since the number of beam injection shots to the storage ring is much less frequent than XFEL shots, one of the XFEL shots must be overridden by an injection with on-demand basis. In addition, the beam quality, such as 1 mm mrad normalized emittance, 10 fs bunch length and 10 kA peak current, must be maintained not to deteriorate the XFEL performance. Therefore, we have developed an on-demand beam route and RF parameter switching system with sufficient speed, precision and reliability. A beam route data is transmitted to each accelerator unit by a reflective memory network, and special software changes the parameters of each accelerator unit pulse-by-pulse according to the received data. We tested the on-demand switching system at a test bench and the SACLA linac. The beam parameters were appropriately controlled with a negligible failure rate. The user service of the beam injection from SACLA to SPring-8 is scheduled in 2020 and the on-demand switching system is almost ready for the time-sharing operation of multiple XFEL beamlines and a SPring-8 injection. T. Hara et al., Phys. Rev. Accel. Beams 21, 040701 (2018).
	Slides THYYPLS1 [8.519 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THYYPLS1
About •	paper received ※ 16 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Design Study of Nonlinear Energy Chirp Correction Using Sextupole Magnets at the Soft X-Ray Free-Electron Laser Beamline of SACLA

1782

K. Togawa, T. Hara, H. Tanaka
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

At the x-ray free-electron laser (FEL) facility, SACLA, a soft x-ray FEL beamline (SCSS+) is driven by a dedicated 800-MeV electron accelerator and being operated in parallel with two hard x-ray FEL beamlines. Responding to the demands of short laser pulses from users, a nonlinearity correction system using sextupole magnets is under consideration to obtain shorter electron bunches. Since the frequency of the SCSS+ injector is S-band, the nonlinearity correction of a bunch compression process using a harmonic correction cavity is not so efficient as the SACLA injector, whose frequency of the injector is L-band. Instead of a complex and costly correction cavity system, the sextupole magnets are simply installed in a dispersive section of the first bunch compressor chicane. In this report, we will present the basic design concept and some detail studies of the nonlinear correction.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB042

About •

paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

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

WEPMP009

Renovation of Off-Axis Beam Injection Scheme for Next-Generation Photon Sources

2318

S. Takano, K. Fukami, C. Kondo, M. Masaki, M. Oishi, M. Shoji, K. Tamura, T. Taniuchi, T. Watanabe, K. Yanagida
JASRI, Hyogo, Japan
H. Akikawa, K. Sato
Nihon Koshuha Co. Ltd, Yokohama, Japan
K. Fukami, T. Hara, T. Inagaki, C. Kondo, M. Oishi, S. Takano, H. Tanaka, T. Watanabe
RIKEN SPring-8 Center, Hyogo, Japan
K. Hamato, J. Kataoka, K. Kusano, K. Ogata, Y. Saito
TOKIN, Sendai, Miyagi, Japan

Funding: Work supported by Ministry of education, culture, sports, science and technology JAPAN (MEXT).
Photon sources are looking for performance upgrades by pursuing higher photon brilliance and coherence these years. The trend is pushing the lattice design to lower the beam emittance, which naturally results in the narrower dynamic aperture. One bottleneck in the upgrades is a beam injection system capable of accumulating required beam intensity and keeping top-up operations with such narrow apertures. Beam injection with a nonlinear kicker and transverse/longitudinal on-axis injections are now in the limelight. However, these techniques still need time to be put into practical use. We take an alternative approach for the SPring-8 upgrade, SPring-8-II, renovating the off-axis beam injection scheme to address the following requirements for the coming diffraction-limited storage rings (DLSRs): minimizing of both injection beam amplitude and perturbation to stored beam, and topping-up functionality. This presentation will overview the renewed off-axis beam injection scheme and report the development status of the following three key components: 1) permanent magnet based DC septum magnet, 2) in-vacuum pulse septum magnet, and 3) twin kickers driven by a single solid state pulser.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP009

About •

paper received ※ 10 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

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

WEPGW029

The Design of the Control System for the SACLA/SPring-8 Accelerator Complex to Use the LINAC of SACLA for a Full-Energy Injector of SPring-8

2529

T. Fukui
RIKEN SPring-8 Center, Innovative Light Sources Division, Hyogo, Japan
T. Hara, N. Hosoda, T. Inagaki, H. Maesaka, T. Ohshima, H. Tanaka
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
T. Hasegawa, O. Morimoto, Y. Tajiri, S. Tanaka, M. Yoshioka
SES, Hyogo-pref., Japan
S. Matsubara, K. Okada
JASRI, Hyogo, Japan
M. Yamaga
JASRI/SPring-8, Hyogo-ken, Japan

At the SPring-8 site, the X-ray free electron laser facili-ty, SACLA, and the third-generation light source, SPring-8 storage ring, have been operated. On the SPring-8 up-grade project we have a plan to use the linac of SACLA as a full-energy injector of the storage ring. To achieve the SACLA’s user operation and the beam injection to the storage ring in parallel, it is necessary to control the beam energy and the peak current on a pulse by pulse. The demand for an injection occurs anytime during the top-up operation of the storage ring. For this purpose, two accel-erators should be controlled seamlessly and the SACLA has to provide the low emittance electron beam to gener-ate X-ray laser and to be an injector of the storage ring simultaneously. Because SACLA has to control the beam energy and peak current on a pulse by pulse, we are de-signing a system to meet these requirements. A master controller stores a pattern of parameters required for the low-level RF controllers. Each pattern consists of 60 rows which correspond to the parameters for one second with a beam repetition rate of the SACLA, 60Hz. The master sends the parameters to the controllers with reflective memory. We can select the pattern every second on de-mand and it is flexible enough for the top-up operation of the storage ring. Also the data of low-level RF and beam position monitor are stored into the database with a beam repetition rate. In this paper, we report the design of con-trol system for SACLA/SPring-8 to control the beam energy and the peak current on a pulse by pulse.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW029

About •

paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

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

THYYPLS1

On-Demand Beam Route and RF Parameter Switching System for Time-Sharing of a Linac for X-ray Free-Electron Laser as an Injector to a 4th-Generation Synchrotron Radiation Source

3427

H. Maesaka, T. Fukui, T. Hara, T. Inagaki, H. Tanaka
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
T. Hasegawa, O. Morimoto, Y. Tajiri, S. Tanaka, M. Yoshioka
SES, Hyogo-pref., Japan
N. Hosoda, S. Matsubara, T. Ohshima
JASRI/SPring-8, Hyogo-ken, Japan
C. Kondo, K. Okada, M. Yamaga
JASRI, Hyogo, Japan

We have an upgrade plan of the SPring-8 storage ring to provide much more brilliant X-rays with a low-emittance electron beam. Since the upgraded ring requires a low-emittance injection beam, we are planning to timeshare the linac of the X-ray free electron laser (XFEL) facility, SACLA, as an injector for the upgraded ring. The SACLA linac delivers low-emittance and short-bunch electron beams to two XFEL beamlines with a 60 Hz repetition rate. The beam route is right now equally changed by a kicker magnet at a switchyard. The beam parameter is also optimized for each XFEL beamline by changing RF parameters pulse-by-pulse with simple software at this moment*. Since the number of beam injection shots to the storage ring is much less frequent than XFEL shots, one of the XFEL shots must be overridden by an injection with on-demand basis. In addition, the beam quality, such as 1 mm mrad normalized emittance, 10 fs bunch length and 10 kA peak current, must be maintained not to deteriorate the XFEL performance. Therefore, we have developed an on-demand beam route and RF parameter switching system with sufficient speed, precision and reliability. A beam route data is transmitted to each accelerator unit by a reflective memory network, and special software changes the parameters of each accelerator unit pulse-by-pulse according to the received data. We tested the on-demand switching system at a test bench and the SACLA linac. The beam parameters were appropriately controlled with a negligible failure rate. The user service of the beam injection from SACLA to SPring-8 is scheduled in 2020 and the on-demand switching system is almost ready for the time-sharing operation of multiple XFEL beamlines and a SPring-8 injection.
* T. Hara et al., Phys. Rev. Accel. Beams 21, 040701 (2018).

Slides THYYPLS1 [8.519 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THYYPLS1

About •

paper received ※ 16 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

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