First test of electropolishing system at impcas

IMP Institution of Modern Physics has designed, fabricated and installed the first SRF cavity electropolishing system of China. It is sized for 1.3GHz SRF cavities, and works for multiple cell cavities with further upgrade of structure. INTRODUCTION Producing high field and Q-values in superconducting RF cavities of niobium has required the removal of a substantial layer of the inner cavity surface, typically of the order of 100 microns in depth. Two methods have commonly been used: EP (electropolishing) or BCP (buffered chemical polish). EP of niobium cavities is proving to yield consistently better performance than BCP [1, 2]. To take advantage of high performance levels obtainable with EP technique, a completed EP system was installed and operated at IMP.