Synchrotron
The largest device of this type seriously proposed was the Superconducting Super Collider (SSC), which was to be built in Texas. This design, like others, used superconducting magnets which allow more intense magnetic fields to be created without the limitations of core saturation.  Its planned ring circumference was 87.1 kilometres (54.1 mi) with an energy of 20 TeV per beam of protons.  Construction was begun in 1991 but later cancelled in 1994. The project had been poorly managed.  Some people say that the end of the Cold War resulted in a change of scientific funding priorities that contributed to its ultimate cancellation.