IPAC2019 - List of Authors (Tanaka, H.)

Paper	Title	Page
TUPMP014	Digital Control System of High Precision Magnet Power Supply for SPring-8-II	1259
	C. Kondo, K. Fukami, S. Takano, T. Watanabe Japan Synchrotron Radiation Research Institute (JASRI), RIKEN SPring-8 Center, Hyogo, Japan T. Fukui, H. Tanaka RIKEN SPring-8 Center, Hyogo, Japan S. Nakazawa SES, Hyogo-pref., Japan N. Nishimori QST, Tokai, Japan C. Saji JASRI/SPring-8, Hyogo-ken, Japan
	For the SPring-8 upgrade plan, SPring-8-II, a variety of magnet power supplies (PS) from 10 W to larger than 100 kW with a high current stability of about 10 ppm (pk-pk, typ.) are required. In order to develop the PSs within a given time and budget, we plan to use a common control system based on a digital control technology that can be adopted for the variety and the high precision PSs. The system consists of a high-precision analog-digital converter (ADC) circuit and a field programmable gate array (FPGA). Since the precision of the ADC circuit determines the current stability of the PS, we first developed the ADC circuit of high accuracy of less than 10 ppm (pk-pk). A proportional-integral (PI) control logic and a digital pulse width modulation (PWM) function was implemented in the FPGA firmware. These functions can be easily modified for each power supply by a desktop computer. We prototyped a DC power supply equipped with the newly developed digital feedback control system and confirmed that the current fluctuation was suppressed to less than 10 ppm (pk-pk). In the presentation, we will report the current status and future perspective of our power supply development including the evaluation results of the new circuits and the power supply we have developed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP014
About •	paper received ※ 16 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
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TUPGW035	A Highly Brilliant Compact 3 GeV Light Source Project in Japan	1478
	N. Nishimori National Institutes for Quantum and Radiological Science and Technology (QST), Sayo-cho, Japan H. Tanaka RIKEN SPring-8 Center, Hyogo, Japan T. Watanabe JASRI/SPring-8, Hyogo, Japan
	A highly brilliant compact 3 GeV light source project was proposed in Japan. The light source would be constructed in Sendai, north-east part of Japan. It provides brilliant soft X-ray beam to widely cover wavelengths ranging from EUV to hard X-ray in Japan together with SPring-8. The accelerator system is now mostly designed except for several linac components and so on. We have chosen a 4-bend achromat lattice to achieve a low emittance keeping a small circumference with a rather relaxed space issue. The number of cells is 16 and the ring circumference is about 350 m. Number of available beam lines are 26 including short straight sections for multi-pole wigglers. Horizontal emittance is expected to be around 1.1 nmrad, and the maximum brilliance may exceed 10²¹ at 1 - 3 keV region with a stored current of 400 mA. The designs of many components such as vacuum chambers, magnets and monitors are employed from those studied for SPring-8 upgrade project. A full energy injector linac equipped with a thermionic gun and C-band accelerating structures is employed to produce sufficiently low emittance beams for efficient beam injections. The C-band system is adopted from those developed for XFEL SACLA with some modifications. In the future, the injector would be upgraded as an electron driver for SXFEL. Details of the project and accelerator system will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW035
About •	paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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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

Digital Control System of High Precision Magnet Power Supply for SPring-8-II

1259

C. Kondo, K. Fukami, S. Takano, T. Watanabe
Japan Synchrotron Radiation Research Institute (JASRI), RIKEN SPring-8 Center, Hyogo, Japan
T. Fukui, H. Tanaka
RIKEN SPring-8 Center, Hyogo, Japan
S. Nakazawa
SES, Hyogo-pref., Japan
N. Nishimori
QST, Tokai, Japan
C. Saji
JASRI/SPring-8, Hyogo-ken, Japan

For the SPring-8 upgrade plan, SPring-8-II, a variety of magnet power supplies (PS) from 10 W to larger than 100 kW with a high current stability of about 10 ppm (pk-pk, typ.) are required. In order to develop the PSs within a given time and budget, we plan to use a common control system based on a digital control technology that can be adopted for the variety and the high precision PSs. The system consists of a high-precision analog-digital converter (ADC) circuit and a field programmable gate array (FPGA). Since the precision of the ADC circuit determines the current stability of the PS, we first developed the ADC circuit of high accuracy of less than 10 ppm (pk-pk). A proportional-integral (PI) control logic and a digital pulse width modulation (PWM) function was implemented in the FPGA firmware. These functions can be easily modified for each power supply by a desktop computer. We prototyped a DC power supply equipped with the newly developed digital feedback control system and confirmed that the current fluctuation was suppressed to less than 10 ppm (pk-pk). In the presentation, we will report the current status and future perspective of our power supply development including the evaluation results of the new circuits and the power supply we have developed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP014

About •

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

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TUPGW035

A Highly Brilliant Compact 3 GeV Light Source Project in Japan

1478

N. Nishimori
National Institutes for Quantum and Radiological Science and Technology (QST), Sayo-cho, Japan
H. Tanaka
RIKEN SPring-8 Center, Hyogo, Japan
T. Watanabe
JASRI/SPring-8, Hyogo, Japan

A highly brilliant compact 3 GeV light source project was proposed in Japan. The light source would be constructed in Sendai, north-east part of Japan. It provides brilliant soft X-ray beam to widely cover wavelengths ranging from EUV to hard X-ray in Japan together with SPring-8. The accelerator system is now mostly designed except for several linac components and so on. We have chosen a 4-bend achromat lattice to achieve a low emittance keeping a small circumference with a rather relaxed space issue. The number of cells is 16 and the ring circumference is about 350 m. Number of available beam lines are 26 including short straight sections for multi-pole wigglers. Horizontal emittance is expected to be around 1.1 nmrad, and the maximum brilliance may exceed 10²¹ at 1 - 3 keV region with a stored current of 400 mA. The designs of many components such as vacuum chambers, magnets and monitors are employed from those studied for SPring-8 upgrade project. A full energy injector linac equipped with a thermionic gun and C-band accelerating structures is employed to produce sufficiently low emittance beams for efficient beam injections. The C-band system is adopted from those developed for XFEL SACLA with some modifications. In the future, the injector would be upgraded as an electron driver for SXFEL. Details of the project and accelerator system will be presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW035

About •

paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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

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

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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

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