This project's aim is to facilitate a better understanding of the current transport in then high temperature superconductor Bi₂Sr₂Ca₁Cu₂O_8+d (Bi-2212). Because this is the only HTS that can be manufactured as a round wire to date, an understanding of the current transport, especially over the grain boundaries, is very important to enable targeted optimization of these wires for technical applications like fusion plants. To this end, different measurement techniques, like magnetization measurements and Hall scans will be used to characterize different Bi-2212 sample types, like single crystals, wires, bulk samples, and thin films. Samples with varying oxygen doping will be compared to examine the dependence of critical material parameters on the doping level. Additionally, some of the suitable samples will be irradiated in the research reactor of the Atominstitut of the TU Wien to measure the changes of characteristic material parameters brought about by the neutron induced defects and to determine the consequences of these defects on the flux pinning.