| | Electro-polishing (EP) experiments are carried out on
niobium samples at Saclay in order to highlight the
influence of parameters such as temperature and acids
concentrations (hydrofluoric and sulfuric). First results
given at the 12th SRF Workshop have been completed.
The importance of the HF/H2O ratio has been precisely
investigated and diluted mixtures have been tested during
long time experiments: removal rates, surface states,
lifetime of the bath and possible hydrogen contamination
will be reported.
In addition, some experiments have been carried out
with dissolved niobium in fresh mixtures, giving some
ideas about mechanisms involved in EP. Furthermore,
dissolved salts as well as different acids have been tried
as an alternative for hydrofluoric acid use. | |