High-resolution computed tomography of two-dimensional beam profile using dual-axis rotating wire.

The use of a wire probe is a robust method for beam profile measurement, but it can only provide a 1D projection of the beam profile. In this study, we developed a novel method for measuring a beam projected from a 360° angle by a dual-axis rotation of a wire and obtaining a complete 2D profile via image reconstruction. We conducted a proof-of-principle study using an Ar+ ion beam and optimized the reconstruction algorithm. The experimental results showed that the use of the order subsets expectation maximization algorithm is the most reasonable method, providing a highly accurate absolute 2D beam profile within a processing time on the millisecond scale. Furthermore, analysis of 2D profiles at different probing positions provided the beam direction and the phase-space distribution. This versatile method can be applied to various fields of particle beam technologies, such as particle therapy, semiconductor processing, and material analysis, as well as basic scientific research.