Beam focusing in a linear ion accelerator consisting of a periodic sequence of independently phased superconducting cavities

Focusing of a low-energy beam of heavy ions in a linear accelerator based on a periodic sequence of independently phased superconducting cavities is considered. The possibility of heavy ion beam focusing by a system of superconducting solenoids is analyzed. The advantages and disadvantages of this focusing technique are considered. It is shown that solenoids with a magnetic field exceeding B = 15 T are required for focusing ion beams with a small charge-to-mass ratio Z/A ≈ 1/66 in a superconducting accelerator.