1. - DNA

2. Simulation of Interactions of Radiation with Biological Systems at the Cellular and DNA Level Based on Sponsored by Activity of S. Agostinelli, S. Chauvie, N. Crompton, R. Corvó, F. Foppiano, S. Garelli, M. Krengli, F. Marchetto, P. Nieminen, M.G. Pia, V. Rolando, A. Solano, G. Sanguineti

3.  The concept of “dose” fails at cellular and DNA scales  It is desirable to gain an understanding to the processes at all levels (macroscopic vs. microscopic+cybernetic)  Quantitative knowledge and strict user requirements scientifically satisfying; may be used as feedback to experimentalists  Potential later connection to other than radiation-induced effects at the cellular and DNA level  Relevance for space: astronaut and airline pilot radiation hazards, biological experiments. Applications in radiotherapy, radiobiology,... Relevance

4. Solar flare electrons, protons, and heavy ions Jovian electrons Solar flare neutrons and  -rays Solar X-rays Galactic and extra-galactic cosmic rays Induced emission (Neutrinos) Trapped particles Anomalous cosmic rays

5. The South Atlantic Anomaly (SAA) Courtesy H. Evans (ESA)

6. Relevance for space: astronaut and aircrew radiation hazards

7. Programme description  -based “sister” activity to the Geant4 Low-E e.m. Working Group. Follows rigorous software standards  ESA-sponsored + INFN official activity  Simulation of nano-scale effects of radiation at the DNA level  Multiple approaches (RBE parameterisation, detailed biochemical processes, etc.) can be implemented with Geant4  First year frame: Collection of user requirements & first prototypes  First Milestone: Wide study of the problem area (completed)  Various scientific domains involved: medical, biology, genetics, software engineering, high and low energy physics, space physics

8. -DNA Collaboration

9. Physical processes Biological processes Chemical processes Process user requirements Courtesy Nature Known, available Unknown, not available E.g. generation of free radicals in the cell User requirements on geometry and visualisation Collection of User Requirements

10. Prototyping 5.3 MeV alpha particle in a cylindrical volume inside cell nucleus. The inner cylinder has a radius of 50 nm.

11. Courtesy A. Brahme (KI)

12.  Completion of Milestone II (rigorous collection of user requirements) to be completed by March 2001  Completion of the current 1-year programme by June 2001  Follow-on activity: code implementation based on user requirements and improved prototypes  Structure of the follow-on activity being outlined Future http://www.ge.infn.it/geant4/dna/