Carbon Coatings :

1
Carbon Coatings - storage - co-sputtering
M.Taborelli , for the SPSU team
2
Storage and aging of a-C air vs N2 for samples
from MBB2 magnet
-Storage in air is made in a polymer box,
possibly too harsh condition -N2 is
beneficial -To be confirmed, only 2 samples for
the moment
3
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 N2 gas ( pump
down and inject N2 gas ) (the most
clean) Samples wrapped in Al foil in air or in
the box.
4
Possible alternative to a-C C-Cu co-deposition
In planar magnetron configuration, at room
temperature Aim more sp2
-shape of the curve points toward
roughness -again N2 storage is good
5
Roughness
Thickness 680 nm (15A)
Thickness 2000 nm (15B)
6
Different aging in air and N2 visible as
oxidation of Cu but it is not necessarily the
effect which increases SEY
7
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