  A vertex detector concept of the Linear Collider Flavour Identification
(LCFI) collaboration, which studies pixel detectors for heavy quark flavour
identification, has been implemented in simulations for c-quark tagging in
scalar top studies. The production and decay of scalar top quarks (stops) is
particularly interesting for the development of the vertex detector as only two
c-quarks and missing energy (from undetected neutralinos) are produced for
light stops. Previous studies investigated the vertex detector design in
scenarios with large mass differences between stop and neutralino,
corresponding to large visible energy in the detector. In this study we
investigate the tagging performance dependence on the vertex detector design in
a scenario with small visible energy for the International Linear Collider
(ILC).
