21/4/2009

Carbon Coatings :- storage - co-sputtering

M.Taborelli , for the SPSU team

21/4/2009

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energy[eV]

SE

Y

MBB_top_20090302_1

MBB#2 top in N2 for 1 month 2009-04-06

MB040 1 month in air 2009-04-06

Storage and aging of a-C: air vs N2 for samples from MBB#2 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

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 N2 gas ( pump down and inject N2 gas ) (the most clean)

Samples wrapped in Al foil in air or in the box.

21/4/2009

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energy [eV]

SE

Y

CAr_p15 B Day1

CAr_p15 B Day 10

CAr_p15 B in N2 for 1 month

CAr_p15 B in air for 1 month

Possible alternative to a-C: C-Cu co-deposition

In planar magnetron configuration, at room temperatureAim: more sp2

-shape of the curve points toward roughness-again N2 storage is good

21/4/2009

Thickness 680 nm (15A)

Thickness 2000 nm (15B)

Roughness

21/4/2009

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924928932936940944948952956960964968972binding energy [eV]

inte

nsi

ty

Cu2p CAr_p15 B initial

Cu2p CAr_p15 B 1 month in air

Cu2p CAr_p15 B 1 month in N2

Cu or Cu2O

CuO orCu(OH)2

Cu2p

Different aging in air and N2 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