IPAC2016 - List of Authors (Ohshima, T.)

Paper	Title	Page
MOPMB028	Development of Beam Diagnostic System for the SPring-8 Upgrade	149
	H. Maesaka, T. Ohshima, Y. Otake RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan H. Dewa, T. Fujita, K. Kobayashi, M. Masaki, S. Matsubara, T. Nakamura, S. Sasaki, S. Takano JASRI/SPring-8, Hyogo-ken, Japan
	The goal of the beam diagnostic system for the SPring-8 upgrade is to deliver brilliant X-rays enabled by the new low-emittance ring to experimental stations with ultimate stability. Developments of accurate electron and photon beam position monitors (EBPM and XBPM, respectively) with both short and long-term stability are the most critical. The EBPM sensitivity is also crucial for low-current beam commissioning to accomplish the first beam storage in the ring. We designed a button electrode to obtain sufficiently high-intensity signals while suppressing high-Q trapped modes leading to impedance and heating issues. We also designed a precise EBPM block and a rigid support to achieve mechanical accuracy and stability. Another challenge is the development of a reliable and stable XBPM, which should be an accurate reference for an orbit feedback without any photon-energy dependences. A significant improvement of a blade-type XBPM or an invention of a novel XBPM detecting the core of an intense X-ray beam are necessary. The other diagnostic instrumentations can be utilized for the new ring with minor improvements.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB028
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMW009	RF System of the SPring-8 Upgrade Project	414
	H. Ego, T. Fujita, N. Hosoda, K. Kobayashi, T. Masuda, S. Matsubara, T. Sugimoto JASRI/SPring-8, Hyogo-ken, Japan T. Asaka, T. Fukui, T. Inagaki, C. Kondo, H. Maesaka, T. Ohshima, T. Sakurai RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
	The RF system of the SPring-8 storage ring has stably generated an accelerating voltage of 16 MV at a frequency of 508.58 MHz since 1997. In the upgrade of the SPring-8, a beam energy is lowered from 8 to 6 GeV and a needed voltage is 7 MV. The upgrade employs multi-bending optics, and shortens the straight sections available for RF accelerating cavities by 30%. On account of the space, the RF system is to be so rearranged that the number of cavities can be reduced to half. The analog low-level RF (LLRF) system in use controls the voltage with sufficiently small deviations of less than 0.1 % in amplitude and less than 0.1 degree in phase, but becomes out-of-dates and hard to be maintained. We plan to replace them with a compact digital LLRF system in the MTCA.4 standard and based on under-sampling scheme. The SACLA linac is used for injecting a low-emittance beam to the ring. Because we have to balance the FEL operation and the beam injection on demand, pulse-by-pulse control of beam parameters is going to be implemented to the SACLA LLRF modules. Furthermore, we build a timing system for injection to a target bucket-position in the ring within a time deviation of 3 ps.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW009
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPOW019	Commissioning Status of the Extreme-Ultraviolet FEL Facility at SACLA	757
	T. Sakurai, T. Asaka, N. Azumi, T. Hara, T. Hasegawa, T. Inagaki, T. Ishikawa, R. Kinjo, C. Kondo, H. Maesaka, T. Ohshima, Y. Otake, H. Tanaka, T. Tanaka, K. Togawa RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan T. Bizen, N. Hosoda, H. Kimura, S. Matsubara, S. Matsui JASRI/SPring-8, Hyogo-ken, Japan
	To equip SACLA with wide ability to provide a laser beams in EUV and soft X-ray regions to experimental users, we have constructed a new free electron laser facility for SACLA beamline-1. Injector components, such as a thermionic electron gun, two buncher cavities, a S-band standing wave accelerator, S-band travelling wave accelerator and their RF sources, were relocated from the SCSS test accelerator, which was a prototype machine of SACLA. At the downstream of a bunch compressor chicane, three C-band 40 MV/m acceleration units were newly installed to effectively boost a beam energy up to 470 MeV. Two in-vacuum undulators were remodeled by changing the period of magnet array from 15 mm to 18 mm to increase SASE intensity by a larger K-value of 2.1. Beam commissioning was started in autumn 2015. So far SASE radiation at a 33 nm wavelength driven by a 470 MeV electron beam was observed. We will install the third undulator in this winter to obtain SASE saturation and additional C-band accelerator units in the next summer to raise the maximum beam energy to 750 MeV. In this presentation, the overview of the facility and the commissioning status will be reported.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOW019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Development of Beam Diagnostic System for the SPring-8 Upgrade

149

H. Maesaka, T. Ohshima, Y. Otake
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
H. Dewa, T. Fujita, K. Kobayashi, M. Masaki, S. Matsubara, T. Nakamura, S. Sasaki, S. Takano
JASRI/SPring-8, Hyogo-ken, Japan

The goal of the beam diagnostic system for the SPring-8 upgrade is to deliver brilliant X-rays enabled by the new low-emittance ring to experimental stations with ultimate stability. Developments of accurate electron and photon beam position monitors (EBPM and XBPM, respectively) with both short and long-term stability are the most critical. The EBPM sensitivity is also crucial for low-current beam commissioning to accomplish the first beam storage in the ring. We designed a button electrode to obtain sufficiently high-intensity signals while suppressing high-Q trapped modes leading to impedance and heating issues. We also designed a precise EBPM block and a rigid support to achieve mechanical accuracy and stability. Another challenge is the development of a reliable and stable XBPM, which should be an accurate reference for an orbit feedback without any photon-energy dependences. A significant improvement of a blade-type XBPM or an invention of a novel XBPM detecting the core of an intense X-ray beam are necessary. The other diagnostic instrumentations can be utilized for the new ring with minor improvements.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB028

Export •

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

MOPMW009

RF System of the SPring-8 Upgrade Project

414

H. Ego, T. Fujita, N. Hosoda, K. Kobayashi, T. Masuda, S. Matsubara, T. Sugimoto
JASRI/SPring-8, Hyogo-ken, Japan
T. Asaka, T. Fukui, T. Inagaki, C. Kondo, H. Maesaka, T. Ohshima, T. Sakurai
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

The RF system of the SPring-8 storage ring has stably generated an accelerating voltage of 16 MV at a frequency of 508.58 MHz since 1997. In the upgrade of the SPring-8, a beam energy is lowered from 8 to 6 GeV and a needed voltage is 7 MV. The upgrade employs multi-bending optics, and shortens the straight sections available for RF accelerating cavities by 30%. On account of the space, the RF system is to be so rearranged that the number of cavities can be reduced to half. The analog low-level RF (LLRF) system in use controls the voltage with sufficiently small deviations of less than 0.1 % in amplitude and less than 0.1 degree in phase, but becomes out-of-dates and hard to be maintained. We plan to replace them with a compact digital LLRF system in the MTCA.4 standard and based on under-sampling scheme. The SACLA linac is used for injecting a low-emittance beam to the ring. Because we have to balance the FEL operation and the beam injection on demand, pulse-by-pulse control of beam parameters is going to be implemented to the SACLA LLRF modules. Furthermore, we build a timing system for injection to a target bucket-position in the ring within a time deviation of 3 ps.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW009

Export •

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

MOPOW019

Commissioning Status of the Extreme-Ultraviolet FEL Facility at SACLA

757

T. Sakurai, T. Asaka, N. Azumi, T. Hara, T. Hasegawa, T. Inagaki, T. Ishikawa, R. Kinjo, C. Kondo, H. Maesaka, T. Ohshima, Y. Otake, H. Tanaka, T. Tanaka, K. Togawa
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
T. Bizen, N. Hosoda, H. Kimura, S. Matsubara, S. Matsui
JASRI/SPring-8, Hyogo-ken, Japan

To equip SACLA with wide ability to provide a laser beams in EUV and soft X-ray regions to experimental users, we have constructed a new free electron laser facility for SACLA beamline-1. Injector components, such as a thermionic electron gun, two buncher cavities, a S-band standing wave accelerator, S-band travelling wave accelerator and their RF sources, were relocated from the SCSS test accelerator, which was a prototype machine of SACLA. At the downstream of a bunch compressor chicane, three C-band 40 MV/m acceleration units were newly installed to effectively boost a beam energy up to 470 MeV. Two in-vacuum undulators were remodeled by changing the period of magnet array from 15 mm to 18 mm to increase SASE intensity by a larger K-value of 2.1. Beam commissioning was started in autumn 2015. So far SASE radiation at a 33 nm wavelength driven by a 470 MeV electron beam was observed. We will install the third undulator in this winter to obtain SASE saturation and additional C-band accelerator units in the next summer to raise the maximum beam energy to 750 MeV. In this presentation, the overview of the facility and the commissioning status will be reported.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOW019

Export •

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