SRF2023 - List of Authors (Yamanaka, M.)

Paper	Title	Page
TUPTB052	A Novel Manufacture of Niobium SRF Cavities by Cold Spray	545
	M. Yamanaka KEK, Ibaraki, Japan K. Shimada Nihon University, College of Engineering, Koriyama, Japan
	Cold spray is a lower-temperature solid-state thermal spray process that deposits metal powder using a heated inert gas through a supersonic nozzle. When the material hits at supersonic speed and reaches the critical speed, the particles themselves are plastically deformed to form a film. The material of the superconducting cavity is niobium, a very expensive rare metal. To reduce the amount of niobium and the cost, we propose a novel manufacturing method of forming a thick niobium film on the surface of a mandrel by cold spray using niobium powder and removing the mandrel to finish a hollow shape. We confirmed the feasibility of the proposed method using a model similar to a 3.9 GHz one-cell cavity. Also, the RRR measurement of the niobium specimen made by cold spray was carried out and the measured value of 11 was obtained. We report on these results.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB052
About •	Received ※ 17 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 29 June 2023 — Issue date ※ 10 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEIXA04	Development of the Directly-Sliced Niobium Material for High Performance SRF Cavities	634
	A. Kumar, H. Araki, T. Dohmae, H. Ito, T. Saeki, K. Umemori, A. Yamamoto, M. Yamanaka KEK, Ibaraki, Japan A. Yamamoto CERN, Meyrin, Switzerland
	For the purpose of cost reduction for the ILC, KEK has been conducting R&D on direct sliced Nb materials such as large grain and medium grain Nb. Single-cell, 3-cell, and 9-cell cavities have been manufactured, and each has demonstrated a high-performance accelerating gradient exceeding 35 MV/m. The results of applying high-Q/high-G recipes, such as two-step baking and furnace baking to these cavities are also shown. Moreover, mechanical tests have been carried out for the beforementioned materials to evaluate their strength for application to the High-Pressure Gas Safety Law. The status of development of these large grain and Medium grain Nb will be presented.
	Slides WEIXA04 [3.773 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEIXA04
About •	Received ※ 18 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 12 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPWB135	A Novel Twin Drive Tuner Mechanism for 1.3 GHz ILC Cavity	914
	M. Yamanaka KEK, Ibaraki, Japan
	A tuner is a device that adjusts the resonant frequency of a cavity. Here we propose a new tuner mechanism for the 1.3 GHz ILC cavity. A bellow is provided in the central portion of the helium tank in the longitudinal direction, and flanges are provided on both sides of the bellows. A linear motion actuator is fixed to the flange on one side, and the frequency is changed by pushing and pulling the flange on the opposite side. Significantly, two linear motion actuators are placed in circumference and working simultaneously. It is named a twin-drive tuner. According to the ILC specification, the cavity has a spring constant of 3 KN/mm, requiring a stroke of 2 mm to adjust the 600 kHz range. A loading force of 6 kN is required. This is shared by two linear motion actuators. We developed a prototype actuator with a loading force of 4 kN per unit. It consists of a stepping motor and a sliding screw with a plastic nut. An experimental device was constructed using this actuator and a 1.3 GHz cavity with a helium tank, and the frequency tuning was evaluated. The displacement between the flanges and the frequency are proportional, both have good linearity, and the slope is 296 kHz/mm.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB135
About •	Received ※ 17 June 2023 — Revised ※ 25 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 17 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

A Novel Manufacture of Niobium SRF Cavities by Cold Spray

545

M. Yamanaka
KEK, Ibaraki, Japan
K. Shimada
Nihon University, College of Engineering, Koriyama, Japan

Cold spray is a lower-temperature solid-state thermal spray process that deposits metal powder using a heated inert gas through a supersonic nozzle. When the material hits at supersonic speed and reaches the critical speed, the particles themselves are plastically deformed to form a film. The material of the superconducting cavity is niobium, a very expensive rare metal. To reduce the amount of niobium and the cost, we propose a novel manufacturing method of forming a thick niobium film on the surface of a mandrel by cold spray using niobium powder and removing the mandrel to finish a hollow shape. We confirmed the feasibility of the proposed method using a model similar to a 3.9 GHz one-cell cavity. Also, the RRR measurement of the niobium specimen made by cold spray was carried out and the measured value of 11 was obtained. We report on these results.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB052

About •

Received ※ 17 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 29 June 2023 — Issue date ※ 10 July 2023

Cite •

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

WEIXA04

Development of the Directly-Sliced Niobium Material for High Performance SRF Cavities

634

A. Kumar, H. Araki, T. Dohmae, H. Ito, T. Saeki, K. Umemori, A. Yamamoto, M. Yamanaka
KEK, Ibaraki, Japan
A. Yamamoto
CERN, Meyrin, Switzerland

For the purpose of cost reduction for the ILC, KEK has been conducting R&D on direct sliced Nb materials such as large grain and medium grain Nb. Single-cell, 3-cell, and 9-cell cavities have been manufactured, and each has demonstrated a high-performance accelerating gradient exceeding 35 MV/m. The results of applying high-Q/high-G recipes, such as two-step baking and furnace baking to these cavities are also shown. Moreover, mechanical tests have been carried out for the beforementioned materials to evaluate their strength for application to the High-Pressure Gas Safety Law. The status of development of these large grain and Medium grain Nb will be presented.

Slides WEIXA04 [3.773 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEIXA04

About •

Received ※ 18 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 12 July 2023

Cite •

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

WEPWB135

A Novel Twin Drive Tuner Mechanism for 1.3 GHz ILC Cavity

914

M. Yamanaka
KEK, Ibaraki, Japan

A tuner is a device that adjusts the resonant frequency of a cavity. Here we propose a new tuner mechanism for the 1.3 GHz ILC cavity. A bellow is provided in the central portion of the helium tank in the longitudinal direction, and flanges are provided on both sides of the bellows. A linear motion actuator is fixed to the flange on one side, and the frequency is changed by pushing and pulling the flange on the opposite side. Significantly, two linear motion actuators are placed in circumference and working simultaneously. It is named a twin-drive tuner. According to the ILC specification, the cavity has a spring constant of 3 KN/mm, requiring a stroke of 2 mm to adjust the 600 kHz range. A loading force of 6 kN is required. This is shared by two linear motion actuators. We developed a prototype actuator with a loading force of 4 kN per unit. It consists of a stepping motor and a sliding screw with a plastic nut. An experimental device was constructed using this actuator and a 1.3 GHz cavity with a helium tank, and the frequency tuning was evaluated. The displacement between the flanges and the frequency are proportional, both have good linearity, and the slope is 296 kHz/mm.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB135

About •

Received ※ 17 June 2023 — Revised ※ 25 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 17 July 2023

Cite •

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