Fusion energy, stellarators, and the Wendelstein 7-X project

According to Ampere's law, curl B = J, an electric current produces rotation of magnetic field lines. In 1951, legendary astrophysicist Lyman Spitzer discovered that magnetic field lines may actually wind around each other even if J=0, a result later rediscovered in other guises, such as the "Berry phase" in quantum mechanics. Spitzer proposed to use it as a key to achieve fusion energy in the laboratory, where it provides a way of thermally insulating a thermonuclear plasma from the surroundings in steady state. His idea has recently been put to a billion-euro test by the Max Planck Society in the Wendelstein 7-X experiment. In this lecture, I will explain Spitzer's fundamental insight and describe this latest experiment in the worldwide quest for fusion energy.

Master students in physics are particularly encouraged to attend this talk which should be enjoyable to non-specialist physicists.