IPAC2014 - List of Authors (Ohkuma, H.)

Paper	Title	Page
MOPRO082	Suppression of Stored Beam Oscillation at Injection by Fast Kicker in the SPring-8 Storage Ring	280
	C. Mitsuda, K. Fukami, K. Kobayashi, M. Masaki, H. Ohkuma, S. Sasaki, K. Soutome JASRI/SPring-8, Hyogo-ken, Japan T. Nakanishi SES, Hyogo-pref., Japan
	When the injection bump orbit is not closed perfectly at the beam injection, the horizontal stored beam oscillation is excited. In the SPring-8 storage ring, many efforts had been paid to reduce the beam oscillation by adjusting the temporal shape and timing of four bump magnets and by applying a counter kick to the residual oscillation, whose amplitude is as large as 0.4mm and the width is as narrow as 500ns. Now, the averaged oscillation amplitude has successfully been suppressed to the level of less than 0.1mm. To confirm the suppression effect, we observed the turn-by-turn photon beam profile at the diagnostics beamline with the insertion device. We confirmed that the light axis oscillation was significantly suppressed by a factor of 5 comparing by applying a counter kick. We also found that the oscillation shape and the oscillation amplitude, which were caused by the timing shift of firing bump magnets, are drastically changed by only timing shift of one magnet. We are considering the feedback scheme to keep the suppression effect at the initial level during the user-time.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO082
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MOPRO083	Design Study of High Brilliant Optics at the SPring-8 Storage Ring	283
	Y. Shimosaki, T. Aoki, K. Fukami, K.K. Kaneki, K. Kobayashi, M. Masaki, C. Mitsuda, H. Ohkuma, M. Shoji, K. Soutome, S. Takano, M. Takao JASRI/SPring-8, Hyogo-ken, Japan
	At the SPring-8 storage ring, design study of beam optics concentrating particularly on increasing brilliance, not flux density, is in progress besides continuous efforts of increasing both brilliance and flux density for the user optics. The natural emittances are theoretically reduced from 2.41 nmrad at 8 GeV to 2.27 nmrad (8 GeV), 1.78 nmrad (7 GeV) and 1.33 nmrad (6 GeV) by utilizing an emittance damping effect by the insertion devices. The designed optics has experimentally been examined at 6 GeV, and the electron beam parameters have been confirmed by measurements at the diagnostics beamlines. * Y. Shimosaki et al., “New Optics with Emittance Reduction at the SPring-8 Storage Ring”, IPAC13, MOPEA027.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO083
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TUOCA03	Production of Quasi-monochromatic GeV Photons by Compton Scattering using Undulator X-ray Radiation at SPring-8	941
	H. Ohkuma, A. Mochihashi, M. Oishi, S. Suzuki, K. Tamura JASRI/SPring-8, Hyogo-ken, Japan N. Muramatsu, H. Shimizu Tohoku University, Research Center for Electron Photon Science, Sendai, Japan T. Nakano RCNP, Osaka, Japan
	Funding: This work is supported by JSPS KAKENHI (Grant-in-Aid for Scientific Research) Grant Number 24241035. Backward Compton scattering (BCS) of X-ray photons emitted by undulator and reflected back by a single crystal from the electron beam can produce a quasi-monochromatic gamma-ray beam up to an energy very close to the electron beam energy. The SPring-8 beam diagnostics beamline (BL05SS) is used to inject a reflected undulator X-ray radiation against 8 GeV stored electron beam and to extract a quasi-monochromatic 8 GeV gamma-ray produced by BCS. BL05SS has conditions to do a pilot experiment to obtain the gamma-ray beam using BCS of X-ray photons from existing undulator. Experimental setup including a Bragg mirror system is now under construction. Preliminary reflectivity measurement of a silicon Bragg mirror using around 10keV photons has been done. Status of the experimental preparation and the future outlook is presented.
	Slides TUOCA03 [1.889 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUOCA03
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Paper

Title

Page

Suppression of Stored Beam Oscillation at Injection by Fast Kicker in the SPring-8 Storage Ring

280

C. Mitsuda, K. Fukami, K. Kobayashi, M. Masaki, H. Ohkuma, S. Sasaki, K. Soutome
JASRI/SPring-8, Hyogo-ken, Japan
T. Nakanishi
SES, Hyogo-pref., Japan

When the injection bump orbit is not closed perfectly at the beam injection, the horizontal stored beam oscillation is excited. In the SPring-8 storage ring, many efforts had been paid to reduce the beam oscillation by adjusting the temporal shape and timing of four bump magnets and by applying a counter kick to the residual oscillation, whose amplitude is as large as 0.4mm and the width is as narrow as 500ns. Now, the averaged oscillation amplitude has successfully been suppressed to the level of less than 0.1mm. To confirm the suppression effect, we observed the turn-by-turn photon beam profile at the diagnostics beamline with the insertion device. We confirmed that the light axis oscillation was significantly suppressed by a factor of 5 comparing by applying a counter kick. We also found that the oscillation shape and the oscillation amplitude, which were caused by the timing shift of firing bump magnets, are drastically changed by only timing shift of one magnet. We are considering the feedback scheme to keep the suppression effect at the initial level during the user-time.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO082

Export •

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

MOPRO083

Design Study of High Brilliant Optics at the SPring-8 Storage Ring

283

Y. Shimosaki, T. Aoki, K. Fukami, K.K. Kaneki, K. Kobayashi, M. Masaki, C. Mitsuda, H. Ohkuma, M. Shoji, K. Soutome, S. Takano, M. Takao
JASRI/SPring-8, Hyogo-ken, Japan

At the SPring-8 storage ring, design study of beam optics concentrating particularly on increasing brilliance, not flux density, is in progress besides continuous efforts of increasing both brilliance and flux density for the user optics. The natural emittances are theoretically reduced from 2.41 nmrad at 8 GeV to 2.27 nmrad (8 GeV), 1.78 nmrad (7 GeV) and 1.33 nmrad (6 GeV) by utilizing an emittance damping effect by the insertion devices. The designed optics has experimentally been examined at 6 GeV, and the electron beam parameters have been confirmed by measurements at the diagnostics beamlines.
* Y. Shimosaki et al., “New Optics with Emittance Reduction at the SPring-8 Storage Ring”, IPAC13, MOPEA027.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO083

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

TUOCA03

Production of Quasi-monochromatic GeV Photons by Compton Scattering using Undulator X-ray Radiation at SPring-8

941

H. Ohkuma, A. Mochihashi, M. Oishi, S. Suzuki, K. Tamura
JASRI/SPring-8, Hyogo-ken, Japan
N. Muramatsu, H. Shimizu
Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
T. Nakano
RCNP, Osaka, Japan

Funding: This work is supported by JSPS KAKENHI (Grant-in-Aid for Scientific Research) Grant Number 24241035.
Backward Compton scattering (BCS) of X-ray photons emitted by undulator and reflected back by a single crystal from the electron beam can produce a quasi-monochromatic gamma-ray beam up to an energy very close to the electron beam energy. The SPring-8 beam diagnostics beamline (BL05SS) is used to inject a reflected undulator X-ray radiation against 8 GeV stored electron beam and to extract a quasi-monochromatic 8 GeV gamma-ray produced by BCS. BL05SS has conditions to do a pilot experiment to obtain the gamma-ray beam using BCS of X-ray photons from existing undulator. Experimental setup including a Bragg mirror system is now under construction. Preliminary reflectivity measurement of a silicon Bragg mirror using around 10keV photons has been done. Status of the experimental preparation and the future outlook is presented.

Slides TUOCA03 [1.889 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUOCA03

Export •

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