1. Thin Film Coatings for SPS-U
November 20, 2007
Progress report
Paolo Chiggiato
in behalf of TS-MME-CCS

2. 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

3. 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

4. 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;

5. 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;

6. Third objective: coating feasibility in the SPS
considering horizontal coating in the experimental areas;
vertical configuration realistic ?
a brainstorming is unavoidable…