1. Budker Inst. of Physics IHEP Protvino MEPHI Moscow Pittsburg University Low Energy Electromagnetic Physics Maria Grazia Pia INFN Genova S. Chauvie, A. De Angelis, G. Depaola, R. Giannitrapani, A. S. Howard, V. Ivanchenko, F. Longo, F. Marchetto, R. Nartallo, P. Nieminen, M.G. Pia, G. Santin, A. Solano on behalf of the Geant4 LowE Electromagnetic Working Group http://www.ge.infn/geant4/lowE ESTEC, 13-15 June 2001

2. ESA Space Environment & Effects Analysis Section How the project started Cosmic rays, jovian electrons X-Ray Surveys of Asteroids and Moons Solar X-rays, e, p Geant3.21 ITS3.0, EGS4 Courtesy SOHO EIT Geant4 Induced X-ray line emission: indicator of target composition (~100 mm surface layer) C, N, O line emissions included BepiColombo mission to Mercury

3. How it evolved • Low energy models (250 eV to 100 GeV) for electrons and photons, based on the LLNL database • Extensions to lower energies foreseen • Alternative models foreseen • Models for positrons foreseen • Low energy models for positive charged hadrons • Ziegler and ICRU databases and parametrisations • Low energy models for negative charged hadrons • Unique to Geant4 • Based on experimental data (where available) + theoretical model • Low energy models for positive charged ions • Negative ions foreseen • Polarised models • Compton already implemented, other in progress

4. Low energy e.m. extensions Fundamental for space and medical applications, neutrino experiments, antimatter spectroscopy etc. e, down to 250 eV (positrons in progress) Barkas effect: models for antiprotons Low energy hadrons and ions models based on Ziegler and ICRU data and parameterisations

5. Top level class diagram

6. Design: electrons

7. Design: photons

8. Hadrons and ions