Design of a 200-MHz Continuous-Wave Radio Frequency Quadrupole Accelerator for Boron Neutron Capture Therapy

TL;DR

This paper presents the design and simulation of a 200-MHz CW RFQ accelerator optimized for boron neutron capture therapy, achieving high transmission efficiency and good error tolerance.

Contribution

It introduces a novel quadrilateral four-vane RFQ design with detailed beam dynamics and electromagnetic analysis for BNCT applications.

Findings

Achieved 98.7% transmission efficiency for 20-mA proton beam

Selected quadrilateral RFQ structure for its advantages in size and processing

Designed tuners and undercuts for frequency tuning and field uniformity

Abstract

A high-intensity continuous wave (CW) radio frequency quadrupole (RFQ) accelerator is designed for boron neutron capture therapy (BNCT). The transmission efficiency of a 20-mA proton beam accelerated from 30 keV to 2.5 MeV can reach 98.7% at an operating frequency of 200 MHz. The beam dynamics has good tolerance to errors. By comparing the high-frequency parameters of quadrilateral and octagonal RFQ cross-sections, the quadrilateral structure of the four-vane cavity is selected owing to its multiple advantages, such as a smaller cross section at the same frequency and easy processing. In addition, tuners and undercuts are designed to tune the frequency of the cavity and achieve a flat electric field distribution along the cavity. In this paper, the beam dynamics simulation and electromagnetic design are presented in detail.