SRF2021 - List of Authors (Tajima, T.)

Paper	Title	Page
TUOFDV02	Observation of Precise Distribution of Trapped Magnetic Flux Due to Quench by M&T Mapping System
	T. Okada Sokendai, Ibaraki, Japan E. Kako, M. Masuzawa, H. Sakai, R. Ueki, K. Umemori KEK, Ibaraki, Japan P. Pizzol, A. Poudel, T. Tajima LANL, Los Alamos, New Mexico, USA
	This study focused on the flux trapping of the superconducting cavity by measuring changes in the spatial magnetic field distribution for the Nb single-cell cavity using the magnetic field and temperature mapping system. The different external magnetic fields were applied when the cavity was vertically tested. The differences of magnetic field distribution were compared before and after flux trapping caused by quenches. The magnetic field mapping measured the magnetic field, including 3 axial directions, outside the equator of the cavity. Moreover, the local heating generated by the magnetic flux trapping was observed locally using temperature mapping. The result shows that the changes in the magnetic field distribution have the magnetic field components towards the quench location. In this presentation, the detail of experiments and results of the change of the magnetic field distribution and the local heating will be presented.
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TUPTEV003	Progress of MgB₂ Deposition Technique for SRF Cavities at LANL	482
	P. Pizzol, L. Civale, D.N. Kelly, I. Nekrashevich, A. Poudel, H.R. Salazar, R.K. Schulze, T. Tajima LANL, Los Alamos, New Mexico, USA
	Since its discovery in 2001, Magnesium Diboride (MgB₂) has had the potential to become a material for cavity manufacturing. Having a transition temperature (Tc) at ~39 K, there is a potential to operate the cavity at ~20 K with cryocoolers. This will open up a variety of applications that benefit from compact high-efficiency superconducting accelerators. We have found a 2-step deposition technique as a viable technique for cavity coating, i.e., coating of a pure boron layer with chemical vapor deposition using a diborane gas in the first step and react it with Mg vapor in the second step. In this paper, we will show some recent results with up to Tc ~38 K using a small furnace and describe a new coating system under construction with a new 3-zone furnace to coat a 1.3-GHz single-cell cavity.
	Poster TUPTEV003 [0.456 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPTEV003
About •	Received ※ 21 June 2021 — Accepted ※ 16 October 2021 — Issue date ※ 02 May 2022
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Paper

Title

Page

TUOFDV02

Observation of Precise Distribution of Trapped Magnetic Flux Due to Quench by M&T Mapping System

T. Okada
Sokendai, Ibaraki, Japan
E. Kako, M. Masuzawa, H. Sakai, R. Ueki, K. Umemori
KEK, Ibaraki, Japan
P. Pizzol, A. Poudel, T. Tajima
LANL, Los Alamos, New Mexico, USA

This study focused on the flux trapping of the superconducting cavity by measuring changes in the spatial magnetic field distribution for the Nb single-cell cavity using the magnetic field and temperature mapping system. The different external magnetic fields were applied when the cavity was vertically tested. The differences of magnetic field distribution were compared before and after flux trapping caused by quenches. The magnetic field mapping measured the magnetic field, including 3 axial directions, outside the equator of the cavity. Moreover, the local heating generated by the magnetic flux trapping was observed locally using temperature mapping. The result shows that the changes in the magnetic field distribution have the magnetic field components towards the quench location. In this presentation, the detail of experiments and results of the change of the magnetic field distribution and the local heating will be presented.

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

TUPTEV003

Progress of MgB₂ Deposition Technique for SRF Cavities at LANL

482

P. Pizzol, L. Civale, D.N. Kelly, I. Nekrashevich, A. Poudel, H.R. Salazar, R.K. Schulze, T. Tajima
LANL, Los Alamos, New Mexico, USA

Since its discovery in 2001, Magnesium Diboride (MgB₂) has had the potential to become a material for cavity manufacturing. Having a transition temperature (Tc) at ~39 K, there is a potential to operate the cavity at ~20 K with cryocoolers. This will open up a variety of applications that benefit from compact high-efficiency superconducting accelerators. We have found a 2-step deposition technique as a viable technique for cavity coating, i.e., coating of a pure boron layer with chemical vapor deposition using a diborane gas in the first step and react it with Mg vapor in the second step. In this paper, we will show some recent results with up to Tc ~38 K using a small furnace and describe a new coating system under construction with a new 3-zone furnace to coat a 1.3-GHz single-cell cavity.

Poster TUPTEV003 [0.456 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPTEV003

About •

Received ※ 21 June 2021 — Accepted ※ 16 October 2021 — Issue date ※ 02 May 2022

Cite •

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