SRF2023 - List of Authors (Ozeki, K.)

Paper	Title	Page
MOIXA04	Operational Experience for RIKEN Superconducting Linear Accelerator	30
	K. Yamada, M. Fujimaki, H. Imao, O. Kamigaito, M. Komiyama, K. Kumagai, T. Nagatomo, T. Nishi, H. Okuno, K. Ozeki, N. Sakamoto, K. Suda, A. Uchiyama, T. Watanabe, Y. Watanabe RIKEN Nishina Center, Wako, Japan
	The RIKEN superconducting heavy-ion linac, so-called SRILAC, has been successfully operating for almost four years, and continuously deliver a heavy ion beam for a super-heavy-element synthesis experiment. The effects of a broken coupler in the early days and four years of operation have resulted in increased X-ray emission levels in several superconducting cavities, which have been successfully corrected by pulse conditioning. This talk will share the experiences and lessons learned from four-year operation with low beta SC-cavities.
	Slides MOIXA04 [4.517 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOIXA04
About •	Received ※ 06 July 2023 — Revised ※ 10 July 2023 — Accepted ※ 19 August 2023 — Issue date ※ 22 August 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPWB085	Degradation and Recovery of Cavity Performance in SRILAC Cryomodules at RIBF	784
	N. Sakamoto, O. Kamigaito, K. Ozeki, K. Suda, K. Yamada RIKEN Nishina Center, Wako, Japan
	The RIKEN superconducting (SC) heavy-ion linear accelerator (SRILAC) has been providing beam supply for super-heavy elements synthesis experiments since its commissioning in January 2020. However, the long-term operation of SC radio-frequency (RF) cavities leads an increase in the X-ray levels caused by field emissions resulting from changes in the inner surface conditions. More than half of the ten SC 1/4 wavelength resonators (SC-QWRs) of SRILAC, operating at a frequency of 73 MHz, have experienced an increase in X-ray levels, thus, requiring adjustments to the acceleration voltage for continuous operation. While several conditioning methods have been employed for SC cavities, a fully established technique is yet to be determined. To address this situation, a relatively simple conditioning method was implemented at RIKEN. The proposed method uses high-voltage pulsed power and imposes a low load on the cavities.
	Poster WEPWB085 [12.789 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB085
About •	Received ※ 13 June 2023 — Revised ※ 26 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 01 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPWB101	Present Status of RIKEN Power Couplers for SRILAC	823
	K. Ozeki, O. Kamigaito, N. Sakamoto, K. Suda, K. Yamada RIKEN Nishina Center, Wako, Japan
	The heavy ion linac of the RIKEN, utilizing superconducting technology, began operations in September 2019. Over the following 13 months, two of the ten superconducting accelerating cavities experienced vacuum leaks from the vacuum windows of the fundamental power couplers (FPCs). Currently, additional vacuum windows are installed on all ten FPCs and the beam supply continues without encountering any major issues with the FPCs. Additionally, the fabrication of ten replacement FPCs has been completed, addressing the underlying issues that led to the deterioration of the vacuum window strength. Currently, we are conducting radio frequency (RF) process of the new FPCs. In addition, we are designing a bias applying component to suppress multipacting in the FPCs. This paper reports the status of these issues related to the FPCs at the RIKEN.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB101
About •	Received ※ 19 June 2023 — Revised ※ 27 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 14 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Operational Experience for RIKEN Superconducting Linear Accelerator

30

K. Yamada, M. Fujimaki, H. Imao, O. Kamigaito, M. Komiyama, K. Kumagai, T. Nagatomo, T. Nishi, H. Okuno, K. Ozeki, N. Sakamoto, K. Suda, A. Uchiyama, T. Watanabe, Y. Watanabe
RIKEN Nishina Center, Wako, Japan

The RIKEN superconducting heavy-ion linac, so-called SRILAC, has been successfully operating for almost four years, and continuously deliver a heavy ion beam for a super-heavy-element synthesis experiment. The effects of a broken coupler in the early days and four years of operation have resulted in increased X-ray emission levels in several superconducting cavities, which have been successfully corrected by pulse conditioning. This talk will share the experiences and lessons learned from four-year operation with low beta SC-cavities.

Slides MOIXA04 [4.517 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOIXA04

About •

Received ※ 06 July 2023 — Revised ※ 10 July 2023 — Accepted ※ 19 August 2023 — Issue date ※ 22 August 2023

Cite •

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

WEPWB085

Degradation and Recovery of Cavity Performance in SRILAC Cryomodules at RIBF

784

N. Sakamoto, O. Kamigaito, K. Ozeki, K. Suda, K. Yamada
RIKEN Nishina Center, Wako, Japan

The RIKEN superconducting (SC) heavy-ion linear accelerator (SRILAC) has been providing beam supply for super-heavy elements synthesis experiments since its commissioning in January 2020. However, the long-term operation of SC radio-frequency (RF) cavities leads an increase in the X-ray levels caused by field emissions resulting from changes in the inner surface conditions. More than half of the ten SC 1/4 wavelength resonators (SC-QWRs) of SRILAC, operating at a frequency of 73 MHz, have experienced an increase in X-ray levels, thus, requiring adjustments to the acceleration voltage for continuous operation. While several conditioning methods have been employed for SC cavities, a fully established technique is yet to be determined. To address this situation, a relatively simple conditioning method was implemented at RIKEN. The proposed method uses high-voltage pulsed power and imposes a low load on the cavities.

Poster WEPWB085 [12.789 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB085

About •

Received ※ 13 June 2023 — Revised ※ 26 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 01 July 2023

Cite •

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

WEPWB101

Present Status of RIKEN Power Couplers for SRILAC

823

K. Ozeki, O. Kamigaito, N. Sakamoto, K. Suda, K. Yamada
RIKEN Nishina Center, Wako, Japan

The heavy ion linac of the RIKEN, utilizing superconducting technology, began operations in September 2019. Over the following 13 months, two of the ten superconducting accelerating cavities experienced vacuum leaks from the vacuum windows of the fundamental power couplers (FPCs). Currently, additional vacuum windows are installed on all ten FPCs and the beam supply continues without encountering any major issues with the FPCs. Additionally, the fabrication of ten replacement FPCs has been completed, addressing the underlying issues that led to the deterioration of the vacuum window strength. Currently, we are conducting radio frequency (RF) process of the new FPCs. In addition, we are designing a bias applying component to suppress multipacting in the FPCs. This paper reports the status of these issues related to the FPCs at the RIKEN.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB101

About •

Received ※ 19 June 2023 — Revised ※ 27 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 14 July 2023

Cite •

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