To rectify the problems of electron clouds observed in RHIC and unacceptable
ohmic heating for superconducting magnets that can limit future machine
upgrades, we started developing a robotic plasma deposition technique for
in−situ coating of the RHIC 316LN stainless steel cold bore tubes based on
staged magnetrons mounted on a mobile mole for deposition of Cu followed by
amorphous carbon (a-C) coating. The Cu coating reduces wall resistivity, while
a-C has low SEY that suppresses electron cloud formation. Recent RF resistivity
computations indicate that 10 {\mu}m of Cu coating thickness is needed. But, Cu
coatings thicker than 2 {\mu}m can have grain structures that might have lower
SEY like gold black. A 15-cm Cu cathode magnetron was designed and fabricated,
after which, 30 cm long samples of RHIC cold bore tubes were coated with
various OFHC copper thicknesses; room temperature RF resistivity measured.
Rectangular stainless steel and SS discs were Cu coated. SEY of rectangular
samples were measured at room; and, SEY of a disc sample was measured at
cryogenic temperatures.Comment: 8 pages, contribution to the Joint INFN-CERN-EuCARD-AccNet Workshop
on Electron-Cloud Effects: ECLOUD'12; 5-9 Jun 2012, La Biodola, Isola d'Elba,
Ital