Application of plasma cleaning to cavities processing

Atmospheric-pressure plasma treatment is an emerging, very versatile and inexpensive technique used in a variety of surface processes such as dry etching, surface treatments and modification of surface wettability. After initial studies on different configurations of RF, MW and DC atmospheric plasma devices we have analyzed the modification of water wettability induced by helium atmospheric plasma. We have applied a resonance atmospheric plasma cleaning step to further clean a 6 GHz Nb seamless cavity observing an increment in the Q0 from 7×106 to 2×107 in only 30 minutes of process. The increased wettability due to the plasma action on the inner cavity surface has proved to enhance the beneficial action of water rinsing pushing the Q0 value further up close to 3×107.