T-shape cells fed with polarized hydrogen or deuterium atoms have been implemented in several storage rings like COSY, DESY or IUCF as polarized internal targets. To inhibit polarization losses of the stored atoms, e.g. by recombination into molecules, different solutions have been adopted for the surface materials. For example, aluminum with its ceramic monolayer of aluminum oxide on top, Teflon or a water ice surface are successfully used. These surface materials are not allowed for the coming polarized storage cell target at LHCb as not compatible with the vacuum system or because of beam interactions. The only allowed material is amorphous carbon coating, but exists so far no experience about possible depolarization effects. For this reason experiments to investigate the recombination rate of polarized hydrogen atoms and the polarization preservation are under way at the research center in Jülich.