| Title |
Symmetric Removal of Niobium Superconducting RF Cavity in Vertical Electropolishing |
| Authors |
- V. Chouhan, Y.I. Ida, K.N. Nii, T.Y. Yamaguchi
MGH, Hyogo-ken, Japan
- H. Hayano, S. Kato, H. Monjushiro, T. Saeki, M. Sawabe
KEK, Ibaraki, Japan
- K. Ishimi
MGI, Chiba, Japan
|
| Abstract |
Vertical electropolishing (VEP) leads several advantages over horizontal EP in respect of easy operation and mechanism of an EP system resulting in lower cost. However, till yet VEP always resulted inhomogeneous removal of a niobium (Nb) cavity along its length and bubble traces especially on the top iris of a vertically set cavity. In this work we performed lab EP and VEP experiments in order to study and solve these two problems. A coupon cavity which contains 6 disk type Nb coupons positioned at beam pipes, irises and equator was vertically electropolished to optimize VEP parameters so as to get almost uniform removal of Nb and a smooth surface of the cavity without bubble traces. Our patented unique i-Ninja cathode having 4 wings was used with an optimized rotation speed to get homogeneous removal of Nb. The homogeneous removal and the surface without bubble traces might be result of a uniform thickness of a viscous layer on the surface of the cavity cell and no accumulation of hydrogen bubbles on the top iris surface. The surfaces of the coupons were studied in detail with surface analytical tools.
|
| Paper |
download MOPB105.PDF [1.704 MB / 5 pages] |
| Conference |
SRF2015, Whistler, BC, Canada |
| Series |
International Conference on RF Superconductivity (17th) |
| Proceedings |
Link to full SRF2015 Proccedings |
| Session |
Poster Session |
| Date |
14-Sep-15 14:20–17:30 |
| Main Classification |
SRF Technology - Processing |
| Keywords |
cavity, cathode, experiment, accumulation, niobium |
| Publisher |
JACoW, Geneva, Switzerland |
| Editors |
Robert E. Laxdal (TRIUMF, Vancouver, BC, Canada); Jana Thomson (TRIUMF, Vancouver, BC, Canada); Volker RW Schaa (GSI, Darmstadt, Germany) |
| ISBN |
978-3-95450-178-6 |
| Published |
December 2015 |
| Copyright |
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