1. Validation of Geant4 Bertini cascade nuclide production Aatos Heikkinen Helsinki Institute of Physics FrontierScience, Milano, September 12-17, 2005

2. Outline ● Validation of Geant4 Bertini cascade nuclide production by proton-induced reactions on various targets ● Comparisons of Geant4 simulated excitation functions against experimental data

3. Geant4 Bertini cascade producing mass-yield curves for proton bombardement of bismuth target For the case of 0.48 GeV protons we see spallation products for A>160 and fission region for A<140 While the energy is increased to the GeV region, the clean-cut distinction between these regions vanishes

5. A characteristic feature of high-energy reactions: after an initially steep rise, exitation function levels off and becomes nearly independent of bombarding energy This is in contrast to a compound-nucleus reaction where the energy transfer is complete and exitation function rapidly comes down after maximum

7. Exitation functions of special interst to underground experiments Germanium from gallium is quite accurately reproduced. But...

8. ... in the case of fluorine from oxygen Bertini cascade underestimates cross- sections At low energies, simulated cross- section agrees better with experimental data

9. Case of mercury from gold

10. Here we study exitation function up to 3.0 GeV Manganese and vanadium isotopes are produced from cobalt targets

11. Usually Bertini models are used below 3 GeV Still we found reasonable performance at 8.1 GeV

12. H. M. Günter, Comparison of Geant4 hadronic models against experimental data. (unpublished)

13. H. M. Günter, Comparison of Geant4 hadronic models against experimental data. (Unpublished) H. M. Günter, Comparison of Geant4 hadronic models against experimental data. (unpublished)

14. Low-energy neutron induced isotope production is usually treated with Geant4 isotope production model using of evaluated data libraries Yet in some cases Bertini model performs quite well and might be useful

15. Conclusion ● We have studied the performance of the isotope production of Geant4 Bertini cascade model ● In most cases the performance was found to be comparable to codes such as CEM, LAHET, or CASCADE ● In case of specific isotope configuration, users can validate Bertini physics with a test-driver available at http://www.hip.fi/geant4/validation