Beam Dynamic Design of IH-DTL with Built-in Permanent Magnet Quadrupole Lens

Based on KONUS dynamics, the beam dynamic design of a compact IH-DTL with built-in permanent magnet quadrupole lens was completed. The DTL consists 37 acceleration cells and two sets of permanent magnet quadrupole lenses, enabling the acceleration of C⁶⁺ ion beam of 20 emA from 0.5 MeV/u to 4.0 MeV/u. Throughout the design process, significant focus was placed on optimizing the voltage of the acceleration gap, the parameters of the quadrupole magnet, the phase setting of the beam injection, and the energy and phase setting of the 0-degree reference particle to control the transverse and longitudinal emittance growth of the high-current ion beam in the low-energy range. Consequently, transverse normalized RMS acceptance of the IH-DTL reaches 0.37 πmm · mrad, and the transmission efficiency exceeds 95%.