Physical Review Special Topics-Accelerators and Beams
Plasma-based surface modification of niobium is a promising alternative to wet etching of superconducting radio frequency (SRF) cavities. We have demonstrated surface layer removal in an asymmetric nonplanar geometry, using a simple cylindrical cavity. The etching rate is highly correlated with the shape of the inner electrode, radio-frequency (rf) circuit elements, gas pressure, rf power, chlorine concentration in the Cl2/Ar gas mixtures, residence time of reactive species, and temperature of the cavity. Using variable radius cylindrical electrodes, large-surface ring-shaped samples, and dc bias in the external circuit, we have measured substantial average etching rates and outlined the possibility of optimizing plasma properties with respect to maximum surface processing effect.
Original Publication Citation
Upadhyay, J., Im, D., Popovic, S., Valente-Feliciano, A.M., Phillips, L., & Vuskovic, L. (2014). Plasma processing of large curved surfaces for superconducting rf cavity modification. Physical Review Special Topics-Accelerators and Beams, 17(12), 122001 . doi: 10.1103/PhysRevSTAB.17.122001
0000-0002-3668-4841 (Popovic), 0000-0002-7202-7283 (Vuskovic)
Upadhyay, J.; Im, Do; Popovic, S.; Valente-Feliciano, A. M.; Phillips, L.; and Vušković, L., "Plasma Processing of Large Curved Surfaces for Superconducting rf Cavity Modification" (2014). Physics Faculty Publications. 43.