IBIC2019 - List of Authors (Ikeda, H.)

Paper	Title	Page
TUPP017	Thermal Performance of Diamond SR Extraction Mirrors for SuperKEKB	332
	J.W. Flanagan, M. Arinaga, H. Fukuma, H. Ikeda, G. Mitsuka, Y. Suetsugu KEK, Ibaraki, Japan E. Mulyani BATAN, Yogyakarta, Indonesia E. Mulyani Sokendai, Ibaraki, Japan
	The SuperKEKB accelerator is a high-current, low-emittance upgrade to the KEKB double ring collider. The beryllium extraction mirrors used for the synchrotron radiation (SR) monitors at KEKB suffered from heat distortion due to incident SR, leading to systematic changes in magnification with beam current, and necessitating continuous monitoring and compensation of such distortions in order to correctly measure the beam sizes.* To minimize such mirror distortions, quasi-monocrystalline CVD diamond mirrors have been designed and installed at SuperKEKB.** Diamond has a very high heat conductance and a low thermal expansion coefficient. With such mirrors it is hoped to reduce the beam current-dependent magnification to the level of a few percent at SuperKEKB. Preliminary measurements of mirror distortion during SuperKEKB commissioning show very promising results with regard to thermal performance, though full beam currents have not yet been stored in the SuperKEKB rings. Measurements of the thermal deformation of the diamond mirrors will be presented in this paper, along with a description of the design of the mirrors and their mounts, and issues encountered during commissioning. M. Arinaga et al., NIM, A499, p. 100 (2003). *J.W. Flanagan et al., "Diamond mirrors for the SuperKEKB synchrotron radiation monitors," Proc. IBIC2012, Tsukuba, Japan p. 515 (2012).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP017
About •	paper received ※ 09 September 2019 paper accepted ※ 10 September 2019 issue date ※ 10 November 2019
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TUPP018	Synchrotron Radiation Monitor for SuperKEKB Damping Ring in Phase-III Operation	336
	H. Ikeda, J.W. Flanagan, H. Fukuma, H. Sugimoto, M. Tobiyama KEK, Ibaraki, Japan
	The SuperKEKB damping ring (DR) commissioned in March 2019, before main ring (MR) Phase-III operation. The design luminosity of SuperKEKB is 40 times that of KEKB with high current and low emittance. We constructed the DR in order to deliver a low-emittance positron beam. A synchrotron radiation monitor (SRM) was installed for beam diagnostics at the DR. Streak camera and gated camera were used for measurement of the damping time and the beam size. This paper shows the design of DR SRM and the result of the measurement.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP018
About •	paper received ※ 04 September 2019 paper accepted ※ 08 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Thermal Performance of Diamond SR Extraction Mirrors for SuperKEKB

332

J.W. Flanagan, M. Arinaga, H. Fukuma, H. Ikeda, G. Mitsuka, Y. Suetsugu
KEK, Ibaraki, Japan
E. Mulyani
BATAN, Yogyakarta, Indonesia
E. Mulyani
Sokendai, Ibaraki, Japan

The SuperKEKB accelerator is a high-current, low-emittance upgrade to the KEKB double ring collider. The beryllium extraction mirrors used for the synchrotron radiation (SR) monitors at KEKB suffered from heat distortion due to incident SR, leading to systematic changes in magnification with beam current, and necessitating continuous monitoring and compensation of such distortions in order to correctly measure the beam sizes.* To minimize such mirror distortions, quasi-monocrystalline CVD diamond mirrors have been designed and installed at SuperKEKB.** Diamond has a very high heat conductance and a low thermal expansion coefficient. With such mirrors it is hoped to reduce the beam current-dependent magnification to the level of a few percent at SuperKEKB. Preliminary measurements of mirror distortion during SuperKEKB commissioning show very promising results with regard to thermal performance, though full beam currents have not yet been stored in the SuperKEKB rings. Measurements of the thermal deformation of the diamond mirrors will be presented in this paper, along with a description of the design of the mirrors and their mounts, and issues encountered during commissioning.
*M. Arinaga et al., NIM, A499, p. 100 (2003).
**J.W. Flanagan et al., "Diamond mirrors for the SuperKEKB synchrotron radiation monitors," Proc. IBIC2012, Tsukuba, Japan p. 515 (2012).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP017

About •

paper received ※ 09 September 2019 paper accepted ※ 10 September 2019 issue date ※ 10 November 2019

Export •

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

TUPP018

Synchrotron Radiation Monitor for SuperKEKB Damping Ring in Phase-III Operation

336

H. Ikeda, J.W. Flanagan, H. Fukuma, H. Sugimoto, M. Tobiyama
KEK, Ibaraki, Japan

The SuperKEKB damping ring (DR) commissioned in March 2019, before main ring (MR) Phase-III operation. The design luminosity of SuperKEKB is 40 times that of KEKB with high current and low emittance. We constructed the DR in order to deliver a low-emittance positron beam. A synchrotron radiation monitor (SRM) was installed for beam diagnostics at the DR. Streak camera and gated camera were used for measurement of the damping time and the beam size. This paper shows the design of DR SRM and the result of the measurement.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP018

About •

paper received ※ 04 September 2019 paper accepted ※ 08 September 2019 issue date ※ 10 November 2019

Export •

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