A Single Crystal Niobium RF Cavity of the TESLA Shape

Journal Article · Thu Aug 09 04:00:00 EDT 2007 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2770686· OSTI ID:21067373

Singer, W; Singer, X; Kneisel, P ^[1]

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1. DESY, Notkestrasse 85, D-22607 Hamburg (Germany)

A fabrication method for single crystal niobium cavities of the TESLA shape was proposed on the basis of metallographic investigations and electron beam welding tests on niobium single crystals. These tests showed that a cavity can be produced without grain boundaries even in the welding area. An appropriate annealing allows the outgassing of hydrogen and stress relaxation of the material without destruction of the single crystal. A prototype single crystal single cell cavity was build. An accelerating gradient of 37.5 MV/m was reached after approximately 110 {mu}m of Buffered Chemical Polishing (BCP) and in situ baking at 120 deg. C for 6 hrs with a quality factor exceeding 2x1010 at 1.8 K. The developed fabrication method can be extended to fabrication of multi cell cavities.

• OSTI ID: 21067373
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 927; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNEALING
CHEMICAL POLISHING
DEGASSING
ELECTRON BEAM WELDING
GRAIN BOUNDARIES
GRAIN SIZE
HYDROGEN
MONOCRYSTALS
NIOBIUM
QUALITY FACTOR
STRESS RELAXATION
SUPERCONDUCTING CAVITY RESONATORS
SUPERCONDUCTORS