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Thin Film Coatings for SPS-U. November 20, 2007 Progress report. Paolo Chiggiato in behalf of TS-MME-CCS. Nitrides and carbides of elements of the 4 th group Already used for accelerators. Carbon based materials: graphite, amorphous, N added.
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Thin Film Coatings for SPS-U November 20, 2007 Progress report Paolo Chiggiato in behalf of TS-MME-CCS
Nitrides and carbides of elements of the 4th group Already used for accelerators Carbon based materials: graphite, amorphous, N added sp2 hybridized amorphous carbon have extraordinarily low SEY, while sp3 hybridized carbon has a high SEY. Amorphous carbon nitride is an interesting coating for multipacting suppression because nitrogen inhibits sp3 hybridization of carbon atoms. Main objectives: - Test both (roughly optimized) materials in the SPS in March ‘08; - Availability of a combined XPS-SEY system by March ’08 - Apply the selected coating techniques to SPS chambers J. Appl. Phys., Vol. 92, No. 1, 1 July 2002
First objective: test both mat. in the SPS in March ‘08 Nitrides sputtering system: • cathode design; • installation of the sputtering system in b. 181; • Ti deposition: thickness profile; • TiN deposition: preliminary plasma stability tests; • TiN samples of different compositions. forthcoming Carbon sputtering system: • cathode available (large furnace heating element); • installation of the sputtering system in b. 181; • C deposition in tubular chambers (F=10 cm) • C:N deposition in tubular chambers (F=10 cm) • C:N optimization of parameters forthcoming
First objective: test both mat. in the SPS in March ‘08 Sample characterization protocol Structural & Metallurgical: • surface morphology (SEM); • thickness measurements (SEM); • structure assessment by X-ray diffraction; • composition by GDOS; • surface composition by XPS .vs. heating T • nanohardness; • adherence tests, thermal cycling; • TiN samples of different compositions. Imminent for C and C:N UHV compatibility: • pumpdown characteristic (porosity); • outgassing rates before and after baking; • thermal desorption; • ESD following baking at different T; • PSD at ESRF;
Second objective: availability of a combined XPS-SEY in March Components availability: • electron gun: order sent; • sample manipulators: imminent order; • vacuum chamber design: ready; • vacuum chamber production: started; • pumping system: defined. Manpower: • PhD student fees maybe shared; • Luigi Leggiero: chamber construction; • Holger Neupert: SEY system installation; • Ivo Wevers: vacuum;
Third objective: coating feasibility in the SPS • considering horizontal coating in the experimental areas; • vertical configuration realistic ? • a brainstorming is unavoidable…