||It has been demonstrated recently
that local magnetic field enhancement can originate from roughness
(e.g. steps at grain boundaries).We want to investigate the quench
observed in superconducting niobium cavities can be related to such
morphological defects. Thus, we need to develop two kinds of tools. 1)
A replica technique that allows reproducing the internal surface of
cavities (non destructive testing). 2) A morphological analysis tool.
Indeed, classical roughness measurements are not relevant to
determinate local curvature radius. This paper describes a new
topological approach dedicated to better characterization of the
surface morphology in regard with field enhancement. This technique has
been applied to Niobium samples treated with different kind of surface
treatments. We also present the first results of this approach applied
to replica taken from cavities near the quench site.