Experiments on dynamo action, magnetorotational instability, and Alfvén waves

At the end of 1999, the dynamo experiments in Riga and Karlsruhe initiated a period of strong activity to simulate the origin and the action of cosmic magnetic fields in the liquid metal laboratory. With main focus on our own efforts, we summarize the recent liquid metal experiments on homogeneous dynamo action and related magnetic instabilities. We delineate our plans for a new liquid sodium facility that will comprise a large scale dynamo experiment based on precession, and a Taylor-Couette experiment for the combined investigation of the magnetorotational instability and of the kink-type Tayler instability. We further discuss the capabilities of alkali metal experiments to study Alfvén waves in a parameter region where the Alfvén speed crosses the sound speed.