A Calcium imaging setup at the single ion hit facility at GSI and its application to the

For a single ion hit facility built to irradiate specific targets inside biological cells, it is necessary to prove that the ions hit the selected targets reliably as the ion hits usually cannot be seen. That ability is traditionally tested either indirectly by aiming at preetched tracks in a nuclear track detector, or directly by making the ion tracks inside cells visible by a stain coupled to special proteins produced in response to ion hits. However, both methods are time consuming and hits can be verified only after the experiment. That means targeting errors in the experiment cannot be corrected during the experiment. Therefore, we developed a fast online hit verification method that measures the targeting accuracy electronically with a spatial resolution of ±1μm before cell irradiation takes place.