TY  - CONF
AU  - Reschke, Detlef
AU  - Arnold, Svenja
AU  - Bate, Christopher
AU  - Ermakov, Alexey
AU  - Ermakova, Elena
AU  - Goedecke, Julia Jirapon
AU  - Iversen, Jens
AU  - Kasprzak, Karol
AU  - Muhs, Andrea
AU  - Klinke, Daniel
AU  - Steder, Lea
AU  - Thie, Jan-Hendrik
AU  - Trelle, Lennart
AU  - Wiencek, Mateusz
TI  - Activities on Medium Grain Niobium at DESY
PB  - JACoW Publishing, Geneva, Switzerland
M1  - PUBDB-2025-02063
SN  - 978-3-95450-256-1
SP  - 568-571
PY  - 2025
N1  - Published by JACoW Publishing under the terms of the Creative Commons Attribution 4.0 license. Any further distribution of this work must maintain attribution to the author(s), the published article's title, publisher, and DOI.
AB  - Within the ITN (ILC Technology Network) activity led by KEK, the so-called ”Medium Grain Niobium” is investigated with respect to its possible application for a large-scale SRF cavity production for the International Linear Collider ILC. In the framework of the KEK-DESY collaboration, the niobium material for two 1.3 GHz single-cell cavities was supplied by KEK. After fabrication and initial surface treatment by electropolishing in industry, the cavities have been tested successfully at DESY with gradients above 40 MV/m after an additional Low-T heat treatment. Subsequently, a heat treatment at medium temperatures around 350° C (Mid-T heat treatment) in the DESY furnace was applied. The vertical cryogenic test showed the typical performance after Mid-T heat treatment for both cavities. The Q-value increased up to (20 - 25) MV/m and achieved up to 3.5 · 10¹⁰. The maximum gradients were limited at 28 MV/m and 30 MV/m by breakdown, respectively. In addition, the effect of Ultra High Vacuum (UHV) heat treatments on state-of-the art fine grain niobium at temperatures between 800° C and 1100° C has been studied on samples with respect to grain growth, mechanical and thermal properties.
T2  - SRF2025 - 22nd International Conference on RF Superconductivity
CY  - 18 Sep 2025 - 26 Sep 2025, Tokyo (Japan)
Y2  - 18 Sep 2025 - 26 Sep 2025
M2  - Tokyo, Japan
LB  - PUB:(DE-HGF)8 ; PUB:(DE-HGF)7
DO  - DOI:10.18429/JACoW-SRF2025-THP32
UR  - https://bib-pubdb1.desy.de/record/631866
ER  -