Investigation of BCP Parameters for Mastery of SRF Cavity Treatment

Mastery of Standard Buffered Chemical Polishing (with mixture of hydrofluoric, nitric and phosphoric acids) is of paramount importance for the treatment of SRF resonators with complex geometry has IFMIF half-wave resonators, in order to control accurately their frequency evolution. Furthermore, strong and unexpected asymmetry in removals has recently been observed after BCP treatment of ESS-medium beta resonators. The goal of this study is to investigate accurately influence of parameters such as surface geometry and orientation, acid temperature, agitation and their coupling on the removal rate. We will also focus on the influence of by-products such has NOx on kinetics. The mixture used is HF(40%)- HNO3(65%)-H3PO4(85%) with ratio 1-1-2.4.