A proton treatment system including a proton accelerator structured to generate a proton beam, a beamline pathway configured to direct the proton beam from the proton accelerator to at least one treatment room, a magnet assembly, including superconducting magnets, located in the beamline pathway and configured to transport the proton beam away from the accelerator into the at least one treatment room, an achromat, configured as an achromatic superconducting magnet assembly, that bends the proton beam away from the proton accelerator toward the at least one treatment room, and a collimator provided inside the achromat and configured to select the proton beam with desired energy levels.