THE SPATIAL-DISTRIBUTION OF POSITRON-EMITTING NUCLEI GENERATED BY RELATIVISTIC LIGHT-ION BEAMS IN ORGANIC-MATTER

The range distributions of positron emitters generated during the stopping process of relativistic light ions in organic matter exhibit a pronounced maximum near the range of the primary particles. The shape of this distribution can be qualitatively understood from a simple Monte Carlo approach of the stopping, fragmentation and decay processes. These results offer the possibility of beam monitoring by means of PET techniques during the tumour therapy with a light ion beam. Furthermore, a refinement of this technique may allow the actual dose distribution to be calculated from PET data.