Riga dynamo under external excitation

During the last two runs of our Riga dynamo experiment, we have also studied regimes without magnetic field saturation. Our facility contains three different sources of external field: the Earth field itself, a field from an electric potential probe for velocity measurement, which contains a permanent magnet and is located in the central sodium flow a couple of cm from the wall. Finally, we can apply a rotating 3D seed field of continuously varying low frequency by a 3-phase coil. The response from dynamo was measured in total by six fluxgate sensors. Field values were recorded within the propeller rotation range 0...2000 rpm in steps of 100 rpm both with and without seed field excitation.