TY - JOUR
T1 - Effect of cathode shape on vertical buffered electropolishing for niobium SRF cavities
AU - Jin, S.
AU - Wu, A. T.
AU - Lu, X. Y.
AU - Rimmer, R. A.
AU - Lin, L.
AU - Zhao, K.
AU - Mammosser, J.
AU - Gao, J.
PY - 2013/9/1
Y1 - 2013/9/1
N2 - This paper reports the research results of the effect of cathode shape during vertical buffered electropolishing (BEP) by employing a demountable single cell niobium (Nb) superconducting radio frequency (SRF) cavity. Several different cathode shapes such as, for instance, bar, ball, ellipsoid, and wheels of different diameters have been tested. Detailed electropolishing parameters including I-V characteristic, removal rate, surface roughness, and polishing uniformity at different locations inside the demountable cavity are measured. Similar studies are also done on conventional electropolishing (EP) for comparison. It is revealed that cathode shape has dominant effects for BEP especially on the obtaining of a suitable polishing condition and a uniform polishing rate in an Nb SRF single cell cavity. EP appears to have the same tendency. This paper demonstrates that a more homogeneous polishing result can be obtained by optimizing the electric field distribution inside the cavity through the modification of the cathode shape given the conditions that temperature and electrolyte flow are kept constant. Electric field distribution and electrolyte flow patterns inside the cavity are simulated via Poisson-Superfish and Solidworks respectively. With the optimal cathode shape, BEP shows a much faster polishing rate of ∼2.5 μm/min and is able to produce a smoother surface finish in the treatments of single cell cavities in comparison with EP.
AB - This paper reports the research results of the effect of cathode shape during vertical buffered electropolishing (BEP) by employing a demountable single cell niobium (Nb) superconducting radio frequency (SRF) cavity. Several different cathode shapes such as, for instance, bar, ball, ellipsoid, and wheels of different diameters have been tested. Detailed electropolishing parameters including I-V characteristic, removal rate, surface roughness, and polishing uniformity at different locations inside the demountable cavity are measured. Similar studies are also done on conventional electropolishing (EP) for comparison. It is revealed that cathode shape has dominant effects for BEP especially on the obtaining of a suitable polishing condition and a uniform polishing rate in an Nb SRF single cell cavity. EP appears to have the same tendency. This paper demonstrates that a more homogeneous polishing result can be obtained by optimizing the electric field distribution inside the cavity through the modification of the cathode shape given the conditions that temperature and electrolyte flow are kept constant. Electric field distribution and electrolyte flow patterns inside the cavity are simulated via Poisson-Superfish and Solidworks respectively. With the optimal cathode shape, BEP shows a much faster polishing rate of ∼2.5 μm/min and is able to produce a smoother surface finish in the treatments of single cell cavities in comparison with EP.
KW - Buffered electropolishing
KW - Electropolishing
KW - I-V characteristics
KW - Niobium SRF cavities
UR - http://www.scopus.com/inward/record.url?scp=84879691069&partnerID=8YFLogxK
U2 - 10.1016/j.apsusc.2013.04.102
DO - 10.1016/j.apsusc.2013.04.102
M3 - Article
AN - SCOPUS:84879691069
SN - 0169-4332
VL - 280
SP - 93
EP - 103
JO - Applied Surface Science
JF - Applied Surface Science
ER -