Carbon Coatings storage cosputtering M Taborelli for the

Carbon Coatings : - storage - co-sputtering M. Taborelli , for the SPSU team 21/4/2009

Storage and aging of a-C: air vs N 2 for samples from MBB#2 magnet -Storage in air is made in a polymer box, possibly too harsh condition -N 2 is beneficial -To be confirmed, only 2 samples for the moment 21/4/2009

Plan for comparison of different storage and SEY aging Storage in polymer box as before Storage in dry air (in desiccators) (less water) Storage in polymer box in large desiccator. (less water, but possibly hydrocarbons) Storage in N 2 gas ( pump down and inject N 2 gas ) (the most clean) Samples wrapped in Al foil in air or in the box. 21/4/2009

Possible alternative to a-C: C-Cu co-deposition In planar magnetron configuration, at room temperature Aim: more sp 2 -shape of the curve points toward roughness -again N 2 storage is good 21/4/2009

Roughness Thickness 680 nm (15 A) Thickness 2000 nm (15 B) 21/4/2009

Different aging in air and N 2 visible as oxidation of Cu …but it is not necessarily the effect which increases SEY 21/4/2009

Other work in progress Investigate relation between a-C coating roughness and substrate temperature Investigate other means to make rough underlayers (electrodeposited Cu, black Cr……. ) Recovery of SEY on a-C with bake-out, sputter-cleaning Improve TDS procedure (geometry of samples) to be able to quantify H concentration in the coatings Produce coatings with applied bias voltage (more compact = less outgassing? ) Investigate the relation between pumpdown and thickness Produce liners more similar to MBB coatings Improve uniformity of coatings in MBA/B geometry 21/4/2009