750MHz radio-frequency quadrupole accelerator designed for medical isotope production

Targeted alpha therapy (TAT) relies on the efficient production of the radionuclide [Formula: see text], which is currently primarily achieved using cyclotrons. However, advances in high-frequency linear accelerator technology offer a new avenue for [Formula: see text] production. While high-frequency linear accelerators serve as a compact alternative, they present significant challenges — most notably for high-frequency radio-frequency quadrupole (RFQ) accelerators, which are constrained by weak transverse focusing strength and the difficulty of achieving longitudinal electric field flatness in long-wavelength RFQs. To enhance beam transmission efficiency, this study optimizes critical parameters (e.g. inter-vane voltage and minimum aperture) and tunes the modulation factor and synchronous phase to balance longitudinal acceleration capability with transverse focusing strength. This optimization yields a transmission efficiency of 90.3% for a 5[Formula: see text]mA [Formula: see text] beam. For longitudinal electric field flattening, a coordinated adjustment approach is developed, which combines 48 tuners with undercut optimization. This method ultimately attains a longitudinal electric field flatness of less than 5%. The reliability of the proposed design is confirmed through multi-code verification and three-dimensional electromagnetic field simulations, while error analysis further reveals substantial tolerance margins for key RFQ parameters.