Search

An apertured microbeam is used for single‐particle single‐cell irradiation to study radiobiological effects at the Radiological Research Accelerator Facility (RARAF), Center for Radiological Research, Columbia University. The present sample targeting system involves imaging techniques and a stepping motor stage to sequentially position a cell nucleus above a vertical ion beam. An interest expressed by the biology research community in targeting subnuclear components has spurred the development of microbeam II, a next‐generation facility to include a focused ion beam and a more precise sample manipulator, a voice coil stage. Sample positioning precision will rely on a feedback circuit incorporating linear variable differential transformer (LVDT) position measurements. In addition, post‐lens electrostatic deflection is a contender for a point‐and‐shoot system that could speed up the cell irradiation process for cells within an image frame. Crucial to this development is that ion beam blow up must be minimal...