SRF2021 - List of Authors (Araki, A.)

Paper	Title	Page
MOPCAV006	High-Q/High-G R&D at KEK Using 9-Cell TESLA-Shaped Niobium Cavities	268
	R. Katayama, A. Araki, H. Ito, E. Kako, T. Konomi, S. Michizono, M. Omet, K. Umemori KEK, Ibaraki, Japan
	We will report on the current progress of High-Q/High-G R&D using three 1.3 GHz 9-cell TESLA shape niobium superconducting cavities at the High Energy Accelerator Research Organization (KEK). These cavities are made of bulk niobium of fine grain material with RRR >300 and have been annealed at 900 degrees for 3 hours. The cavity performances were evaluated at the Superconducting RF Test Facility at KEK (KEK-STF) after 2-step bake (70-75°C 4 h + 120°C 48 h), electropolishing at low temperature, and fast cooling procedure were applied to these cavities. In this study, obtained results will be compared with the baseline measurement for the standard recipe at KEK.
	Poster MOPCAV006 [1.880 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-MOPCAV006
About •	Received ※ 22 June 2021 — Revised ※ 14 January 2022 — Accepted ※ 22 February 2022 — Issue date ※ 28 February 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPFAV003	Stable Beam Operation at 33 MV/m in STF-2 Cryomodules at KEK	382
	Y. Yamamoto, M. Akemoto, D.A. Arakawa, A. Araki, S. Araki, A. Aryshev, T. Dohmae, M. Egi, M.K. Fukuda, K. Hara, H. Hayano, Y. Honda, T. Honma, H. Ito, E. Kako, H. Katagiri, R. Katayama, M. Kawamura, N. Kimura, Y. Kojima, Y. Kondou, T. Konomi, M. Masuzawa, T. Matsumoto, S. Michizono, Y. Morikawa, H. Nakai, H. Nakajima, K. Nakanishi, M. Omet, T. Oyama, T. Saeki, H. Sakai, H. Shimizu, S.I. Takahara, R. Ueki, K. Umemori, A. Yamamoto KEK, Ibaraki, Japan S. Aramoto Hiroshima University, Higashi-Hiroshima, Japan M. Kuriki Hiroshima University, Graduate School of Science, Higashi-Hiroshima, Japan Z.J. Liptak HU/AdSM, Higashi-Hiroshima, Japan K. Sakaue The University of Tokyo, The School of Engineering, Tokyo, Japan A. Yamamoto CERN, Meyrin, Switzerland
	In STF at KEK, as the operational demonstration of the SRF accelerator for ILC, the STF-2 cryomodules (CM¹⁺CM2a: one and half size CM with 12 cavities) have achieved 33 MV/m as average accelerating gradient with 7 cavities in Mar/2019. After that, one cavity with the lowest performance installed in CM2a was replaced with one N-infused cavity developed for High-Q/High-G R&D between Japan and US. From this April, the beam operation started again and those CMs achieved 33 MV/m as average accelerating gradient with 9 cavities including one N-infused cavity again. This is the very important milestone for ILC. In this report, the detailed results will be presented.
	Poster TUPFAV003 [3.020 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPFAV003
About •	Received ※ 21 June 2021 — Revised ※ 11 July 2021 — Accepted ※ 21 August 2021 — Issue date ※ 01 November 2021
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

FROFDV01	Systematic Investigation of Mid-T Furnace Baking for High-Q Performance	881
	H. Ito, A. Araki, K. Umemori KEK, Ibaraki, Japan K. Takahashi Sokendai, Ibaraki, Japan
	We report on an investigation of the effect of a new baking process called "furnace baking" on the quality factor. Furnace baking is performed as the final step of the cavity surface treatment; the cavities are heated in a vacuum furnace in a temperature range of 200-800C for 3 h, followed by high-pressure rinsing and radio-frequency measurement. We find the anti-Q-slope for cavities furnace-baked at a temperature range of 250 to 400C and a reduction in the residual resistance for all cavities. In particular, an extremely high Q value of 5·10¹⁰ at 16 MV/m and 2.0 K is obtained for cavities furnace-baked at 300C.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-FROFDV01
About •	Received ※ 21 June 2021 — Accepted ※ 24 February 2022 — Issue date ※ 30 April 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

High-Q/High-G R&D at KEK Using 9-Cell TESLA-Shaped Niobium Cavities

268

R. Katayama, A. Araki, H. Ito, E. Kako, T. Konomi, S. Michizono, M. Omet, K. Umemori
KEK, Ibaraki, Japan

We will report on the current progress of High-Q/High-G R&D using three 1.3 GHz 9-cell TESLA shape niobium superconducting cavities at the High Energy Accelerator Research Organization (KEK). These cavities are made of bulk niobium of fine grain material with RRR >300 and have been annealed at 900 degrees for 3 hours. The cavity performances were evaluated at the Superconducting RF Test Facility at KEK (KEK-STF) after 2-step bake (70-75°C 4 h + 120°C 48 h), electropolishing at low temperature, and fast cooling procedure were applied to these cavities. In this study, obtained results will be compared with the baseline measurement for the standard recipe at KEK.

Poster MOPCAV006 [1.880 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-MOPCAV006

About •

Received ※ 22 June 2021 — Revised ※ 14 January 2022 — Accepted ※ 22 February 2022 — Issue date ※ 28 February 2022

Cite •

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

TUPFAV003

Stable Beam Operation at 33 MV/m in STF-2 Cryomodules at KEK

382

Y. Yamamoto, M. Akemoto, D.A. Arakawa, A. Araki, S. Araki, A. Aryshev, T. Dohmae, M. Egi, M.K. Fukuda, K. Hara, H. Hayano, Y. Honda, T. Honma, H. Ito, E. Kako, H. Katagiri, R. Katayama, M. Kawamura, N. Kimura, Y. Kojima, Y. Kondou, T. Konomi, M. Masuzawa, T. Matsumoto, S. Michizono, Y. Morikawa, H. Nakai, H. Nakajima, K. Nakanishi, M. Omet, T. Oyama, T. Saeki, H. Sakai, H. Shimizu, S.I. Takahara, R. Ueki, K. Umemori, A. Yamamoto
KEK, Ibaraki, Japan
S. Aramoto
Hiroshima University, Higashi-Hiroshima, Japan
M. Kuriki
Hiroshima University, Graduate School of Science, Higashi-Hiroshima, Japan
Z.J. Liptak
HU/AdSM, Higashi-Hiroshima, Japan
K. Sakaue
The University of Tokyo, The School of Engineering, Tokyo, Japan
A. Yamamoto
CERN, Meyrin, Switzerland

In STF at KEK, as the operational demonstration of the SRF accelerator for ILC, the STF-2 cryomodules (CM¹⁺CM2a: one and half size CM with 12 cavities) have achieved 33 MV/m as average accelerating gradient with 7 cavities in Mar/2019. After that, one cavity with the lowest performance installed in CM2a was replaced with one N-infused cavity developed for High-Q/High-G R&D between Japan and US. From this April, the beam operation started again and those CMs achieved 33 MV/m as average accelerating gradient with 9 cavities including one N-infused cavity again. This is the very important milestone for ILC. In this report, the detailed results will be presented.

Poster TUPFAV003 [3.020 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPFAV003

About •

Received ※ 21 June 2021 — Revised ※ 11 July 2021 — Accepted ※ 21 August 2021 — Issue date ※ 01 November 2021

Cite •

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

FROFDV01

Systematic Investigation of Mid-T Furnace Baking for High-Q Performance

881

H. Ito, A. Araki, K. Umemori
KEK, Ibaraki, Japan
K. Takahashi
Sokendai, Ibaraki, Japan

We report on an investigation of the effect of a new baking process called "furnace baking" on the quality factor. Furnace baking is performed as the final step of the cavity surface treatment; the cavities are heated in a vacuum furnace in a temperature range of 200-800C for 3 h, followed by high-pressure rinsing and radio-frequency measurement. We find the anti-Q-slope for cavities furnace-baked at a temperature range of 250 to 400C and a reduction in the residual resistance for all cavities. In particular, an extremely high Q value of 5·10¹⁰ at 16 MV/m and 2.0 K is obtained for cavities furnace-baked at 300C.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-FROFDV01

About •

Received ※ 21 June 2021 — Accepted ※ 24 February 2022 — Issue date ※ 30 April 2022

Cite •

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