Precession-driven dynamos are to be investigated within DRESDYN (DREsden Sodium facility for DYNamo and thermohydraulic studies) at the HZDR (Helmholtz Zentrum Dresden Rossendorf) in an experiment that is unique in its scale. The dynamo effect describes the self-excitation of a magnetic field from the interactions of the flows of an electrically conductive fluid. Dynamos driven by precession are considered to be the cause of the formation of cosmic magnetic fields, such as the Earth's magnetic field. The precise relationships between the flow and the properties of the excited magnetic fields are the subject of current astrophysical research.

The experiment consists of a cylinder filled with 4 tonnes of liquid sodium with a height of 2.0 m and a radius of 1.0 m. This cylinder is to be rotated at a frequency of up to 10 Hz and precessed at up to 1 Hz. The resulting flow states are to be recorded and their suitability for magnetic field excitation investigated.

As part of the project, the MSE Lab is developing an ultrasonic sensor network that enables the flow state to be recorded in real time. Pre-processed measurement data is to be transmitted by radio for process control and stored in high resolution on the sensor nodes for subsequent fine evaluation.

The first tests are currently being carried out on the system at the HZDR
https://www.hzdr.de/db/VideoDl?pOid=73568&pCid=815

The first iteration of a sensor node is currently being validated in a flow channel and is being used for previously impossible radial measurements on a preliminary experiment (preliminary test setup, preliminary test in use)

A second highly integrated version of the sensor node (photo of IUP v0.2) is currently being evaluated and prepared for tests in a centrifuge. During these tests, the electronics will be exposed to accelerations of up to 400g.

Once the validation phase has been completed, the first measurements on the large-scale experiment are planned.