IPAC2019 - List of Authors (Kondo, C.)

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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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)

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

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)

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)