Design the heavy ion IH-DTL based on KONUS and EQUUS beam dynamics

The Interdigital H-mode (IH) structure is one of the most widely used structures in the room temperature low energy heavy ion linacs. This paper presents the physics design of a heavy ion IH drift tube linac (IH-DTL) which accelerates particles with a charge-to-mass ratio of 1/7 from 0.35[Formula: see text]MeV/u to 1.597[Formula: see text]MeV/u operates at 81.25[Formula: see text]MHz. Two approaches of beam dynamics design employing the KONUS (Combined Zero Degree Structure) and EQUUS (Equidistant Multigap Structure) beam dynamics schemes are performed. The solution based on KONUS beam dynamics scheme includes two RF cavities with 57 gaps and four quadrupole triplets, covering approximately 6.35[Formula: see text]m and achieving 100% transmission efficiency. The one based on EQUUS beam dynamics scheme features 7 10-gap accelerating cavities and 7 doublet quadrupole lenses for the same acceleration, resulting in 7.077[Formula: see text]m in length and 100% transmission efficiency. The electromagnetic design of the cavities and detailed multi-particle simulations for the two solutions are conducted. In comparison, KONUS beam dynamics offers a high acceleration gradient and a more compact accelerator design. However, it is challenging in tuning and processing, and the manufacture cost is high. EQUUS scheme ensures excellent beam quality and emittance growth for heavy ion acceleration. Although the cavity is simple, it has a large number of cavities, which affect the overall power consumption. If combined with a small solid-state power source, the reliability and economy of the scheme can be improved.