Positioning magnets inside the tunnel of the Alternating Gradient Synchrotron at the Brookhaven National Laboratory.
The pep storage ring tunnel is one of two operational electron positron storage rings located at SLAC (Stanford Linear Accelerator).
This photo was taken at the Argonne National Laboratory. The Messner Effect is the expulsion of a magnetic field from a supercomputer during its transition to the superconducting state. Walther Messner and Robert Ochdenfeld discovered the phenomenon in 1933 by measuring the magnetic field distribution outside superconducting tin and lad samples.