A proton therapy facility using a compact, high-field nonsuperconducting cyclotron was first presented by lon Beam Applications (IBA) at the PTCOG meeting in June 1990. In December 1990, funding was secured to start the design of a prototype at IBA. In October 1991 a collaboration agreement was signed between IBA and Sumitomo Heavy Industries (SHI). The main features of this accelerator were presented elsewhere [W. Beeckman et al., Nucl. Instr. and Meth. B56/57 (1991) 1201]. The induction profile in the vicinity of the extraction radius was improved by the introduction of a magnetic shunt resulting in a completely closed gap at the median plane. The extraction system is also described. First calculations on the central region were performed using a simplified 2-D model with stacking factors in order to describe its actual 3-D geometry. Two types of isocentric gantries, namely a scanning gantry as initially proposed and a scattering gantry, are currently designed. Their status is presented in this paper.
Jongen, Y., Laisne, A., Beeckman, W., Dufour, JP., Marie, H., Verbruggen, R., Wollnik, H., Takahashi, N., Satoh, S., Sano, M., & Takayama, T. (2004). Progress Report On the Iba Shi Small Cyclotron for Cancer-therapy. Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms, 79(1-4), 885-889. https://hdl.handle.net/2078.5/145254 (Original work published 2004)