Secondary Electron Yield Laboratory R&D
The system used to measure Secondary Electron Yield (SEY), shown in figure below and thoroughly described in [1], is composed of two coupled stainless steel UHV chambers in which the pressure is in the low 0.1 nTorr range in the measurement chamber and high nTorr range in the load lock chamber. Samples individually screwed to a carrier plate, are loaded first onto an aluminium transfer plate in the load lock chamber, evacuated to a low 10 nTorr scale, and then transferred to the measurement chamber. Pressures are in Torr equivalent N2. The measurement chamber has two electron guns and a soft (1.49 keV x-ray source. One electron gun (energy, 1-3 keV) is used for SEY and SEM, and the other is a "flood" gun for electron conditioning. The x-ray source is used to excite photoelectrons for surface chemical valence and stoichiometry analysis, called ESCA (Electron Spectroscopy for Chemical Analysis), also called XPS (X-ray Photoelectron Spectroscopy). The information depth for XPS is < 5 nm, much less than the thickness of the samples in this study.
Status: measurements TiN/Al rectangular groove samples and TiZrV coating from LBNL.
Acc. Design Responsible: R. Kirby.
Collaboration: in collaboration with Linear collider LC Div.SLAC.
SEY meauserements for LC: R. Kirby, M. Pivi, F. Le Pimpec LC, G. Collet, F. King.
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