Collaborative planning for ion physics activities M.G. Pia et al. Geant4 Workshop Bordeaux, 7-10 November 2005

A relatively new domain… Not much attention devoted to ion interactions in Geant4 so far other priorities, not lack of interest we have the chance to “do it right” from the beginning, if we agree on a coherent plan of activities and we work at it collaboratively Needed in various application domains: increasing interest high energy physics space science medical physics (hadrontherapy) What are the requirements from the various application domains? Sound requirements engineering would be desirable Requirements from different communities may partly overlap, but also exhibit peculiar experimental needs

Current status Let him who knows what is currently in Geant4 cast the first stone… Not only a hadronic physics issue Transparency and documentation to be improved in EM domain too Documenting what is actually available would already be a significant step forward documenting = understanding the physics model, its assumptions, its parameters, its applicability limits, references in literature etc. Quantitative documentation of validation of existing physics models is the first step needed identify how good what we have is identify areas where improvements are needed evaluate is expectations for improvement are indeed realistic

Open questions… Work still needed in the EM processes for ions Design iteration urgently needed to provide adequate precision both for hadrons and ions current critical situation due to uncontrolled design change w.r.t. original design e.m. physics e.m. + Binary ion set Susanna’s talk at MC 2005 GCR α The contribution of the hadronic interactions looks negligible in the calculation of the energy deposit

Build physics on solid ground It is a difficult physics domain Proliferation of physics models, parameters and “variations on the theme” is expected over a long time scale Sound design is mandatory Software development discipline facilitates transparency of physics Build testing into the physics process development itself

Vision Coordination with related projects Geant4-DNA Hadrontherapy: physics + biological effects of radiation Radiation protection see Susanna’s PhD thesis (Radiation protection in interplanetary manned missions) Radiation background at LHC Space science etc.

Scenario for Aurora Geant4 macroscopic physics processes + biological processes at cellular level Geant4 simulation space environment + spacecraft, shielding etc. anthropomorphic phantom Dose in organs at risk Oncological risk to astronauts Risk of nervous system damage Phase space input to nano-simulation Geant4 macroscopic processes + DNA processes