Recent development for lowenergy package

1. Recent development for lowenergy package V.Ivanchenko Budker Institute for Nuclear Physics Novosibirsk, Russia

2. Main activity in 2002 • Electron ionisation • Electrom Bremssrahlung • Hadron ionization • GenericIons ionisation • Interface to deexcitation module • Fluctuations V.Ivanchenko

3. Electron energy loss in G4 lowenergy package • Is based on EEDL database data on cross sections and spectra • In G4 3.2 there were serious problems in electron processes • Redesign electron physics is available from 4.0, 4.1-ref-02 – fix main problems • Parameterization of 7650 atomic shells V.Ivanchenko

4. Electron bremsstrahlung in G4 4.0 F(x) parametrised from EEDL. At high energies: Continuous energy loss Direction of the outgoing electron thesame as that of the incoming one; angular distribution of emitted photons generated according to a simplified formula based on the Tsai cross section (expected to become isotropic in the low-E limit) Gamma ray production V.Ivanchenko

5. Electron ionisation in G4 4.0 Bs is the binding energy of sub-shell s Continuous energy loss Value of coefficient A for each element is obtained from fit to EEDL data for energies available in the database d-electron production V.Ivanchenko

6. Problems of G4 4.0 parameterization • 50% of level spectra for ionization had problems • For part of atoms dE/dx was not fit standard results at 1-10 MeV energy region • Bremsstrahlung spectra at max energies do not fit standard V.Ivanchenko

7. Solutions for G4 4.1 • For both processes for each shell and atom energy scale for secondary is subdivided on 2 parts – one the same as G4 4.0, in second value A is parameterized • Results of comparison EEDL data and ionization parameterization: • 3034 shells are inside 1 % • 4448 shells are inside 10 % • 168 shells are outside 10 % • Average RMS 2.2 % (17 % in G4 4.0) V.Ivanchenko

8. Comparison with SANDIA electron data • Ionisation profile in media from 1MeV electron strongly depends on multiple scattering • LowEnergy package has small advantage to standard for small step sizes V.Ivanchenko

9. Delta-electron production Si Be V.Ivanchenko

10. Delta-electron production Fe Pb V.Ivanchenko

11. Bremsstahlung Si Be V.Ivanchenko

12. Bremsstahlung Fe Pb V.Ivanchenko

13. Current problems • Angular spectrum of Bremsstrahlung for low energies • 168 non perfect shells • 1 – 10 MeV energy range for some elements has problems • Range artifact V.Ivanchenko

14. Hadron ionisation V.Ivanchenko

15. Hadron ionisation • For the proton energy range 1-2 MeV are not perfect for some atoms for all available models • SRIM-2000 parameterization are welcome V.Ivanchenko

16. Ion ionisation • Ionisation for GenericIons in G4 4.1 • Bragg peak position and right side are perfect • Left side is not so precise V.Ivanchenko

17. Conclusions and plans • List of problems to be fixed to G4 5.0: • Range artifact • Fluo artifact • Range of heavy ions • Angular distribution for Bremsstrahlung can be improved • SRIM-2000 for hadrons and ions? • Model approach will improve quality V.Ivanchenko