Abstract : This joint experimental and theoretical project concerns rotating spoke phenomena in Hall thrusters. This is an international collaborative project between the CARE Institute (CNRS) in France, the High Performance Computing (HPC) group at the Ernst-Moritz-Arndt University in Germany, and the Princeton Plasmas Physics Laboratory in the USA. The main objective of this joint project was to obtain a better understanding of spoke physics through careful experiments and accompanying numerical simulations. The main task was the investigation of the influence of the spoke on the ion flow and its role in thrust and specific impulse generation as well as on the accelerating potential in a Cylindrical Hall Thruster (CHT). We also examine the rotating spoke instability formation and dynamics such as frequency, shape, and mode number and the electron transport arising from the spoke.