Assume the earth’s magnetic field of 0.13 Gauss is used to makea storage ring 110 km above the equat

Assume the earth’s magnetic field of 0.13 Gauss is used to makea storage ring 110 km above the equator, where the vacuum is prettygood, and the space shuttle can be used to perform experiments.What (total) energy protons could be stored in it? The earth’sradius is 6350 km. . . .