A compact biological cell irradiation system with a Van de Graaff accelerator

This report describes the development of a compact microcell irradiation system in the 3 MV KN Van de Graaff accelerator in the Accelerator Laboratory of National Tsing Hua University (NTHU). The main feature of this system is backscattering, a technique whereby a 100 nm gold scattering foil is placed in the center of a scattering chamber, instead of a 90° bending magnet. The incident particles produced by the accelerator bombard the scattering foil and scatter isotropically. A set of micro pinholes was installed above the scattering foil and directed the 90° scattering particles to irradiate the cell target. This innovation simplifies the system design and massively reduces the cost and space requirements for system construction.