Presentation on theme: "Pete Truscott QinetiQ Space LoB"— Presentation transcript:
1Pete Truscott QinetiQ Space LoB DPMJET-II.5 and DPMJET-III Implementation in Geant4 Overview & Status ReportPete TruscottQinetiQ Space LoB03 July 2008
2Implementation of DPMJET-II.5 model in Geant4 (1) Existing FORTRAN code DPMJET-II.5 to act as an event generator:5GeV/nuc to 1E+11 GeV/nucapplicable to all projectiles & targetsPoorly documented code: no explanation of the design / organisation of the code; each subroutine having little (or often no) description; little explanation of internal variables/common blocksGeant4 DPMJET-II.5 interface: G4DPMJET2_5Model class now developed and under testAfter prompt nuclear-nuclear collisions, nuclear de-excitation treated using other Geant4 models (precompound, evaporation, Fermi break-up)Default is precompound, but user can override and declare her own precompound, G4ExcitationHandler or no de-excitation.DPMJET-II.5 FORTRAN code requires Glauber profile data: integral probability function used to sample impact parameterFor Geant4 implementation, determined as a function of AP and AT rather than (AP, ZP) and (AT, ZT)Current version of database of Glauber profile data available applicable to projectiles from AP = 2 to AP = 58 on target nuclei with AT = 2 to AT = 58It is hoped that this will be expanded in due course to projectiles up to A=240 and similarly for targets, but time for generating data extensive (it took ~10 CPU months for A=2 to A=58)
3Implementation of DPMJET-II.5 model in Geant4 (2) Total inelastic cross-sectionsTotal inelastic cross-section class G4DPMJET2_5CrossSection created to do this, and also covers projectiles from A=2 to A=58 on targets from A=2 to A=58 (by-product of DPMJET-II.5)Some comparisons performed at the low-energy (~5GeV) end of the cross-section curve, but limited available data for total inelastic cross-sections at ultra-relativistic energies – does anyone know of any data?S/W CompatibilityTested with G4 v8.3 (tested at reference tag 0), v9.0 (patch 01), v9.1 (tested at reference tag 3) (so I have been told!) built with compiler versions:gcc v3.2.3 with g77 v3.2.3gcc v4.0.0 with g77 v3.2.3gcc v4.2.0 with gfortran v4.2.0gcc v4.2.3 with gfortran v4.2.3WARNING: DPMJET-II.5 FORTRAN has problems with gfortran v4.0.0 and gfortran v4.1.0 (see software manual); it’s possible that latter will work with 32-bit machines.
4Implementation of DPMJET-II.5 model in Geant4 (3) Use in physics listG4ExcitationHandler *theExcitationHandler = new G4ExcitationHandler;G4Evaporation * theEvaporation = new G4Evaporation;G4FermiBreakUp * theFermiBreakUp = new G4FermiBreakUp;theExcitationHandler->SetEvaporation(theEvaporation);theExcitationHandler->SetFermiModel(theFermiBreakUp);theExcitationHandler->SetMaxAandZForFermiBreakUp(17, 9);theDPM = new G4DPMJET2_5Model(DEFAULT);theDPM->SetExcitationHandler(theExcitationHandler);theDPM->SetMinEnergy(6*GeV);theDPM->SetMaxEnergy(100*TeV);Notes/other constraints:Interactions of heavy ions on protons currently ignored (G4DPMJET2_5Model doesn’t currently treat protons)QinetiQ has not included DPMJET-II.5 FORTRAN with release, but easy to download from Ranft’s web-site (see G4dpmjet2_5 software manual)Scripts included with G4dpmjet2_5 to apply patch the DPMJET-II.5 FORTRAN source before compilationInstructions in software manual on how to install & build G4dpmjet2_5, and modifications required to user’s GNUmakefile
5Secondary proton energy spectra from A-A collisions G4dpmjet2_5 & FLUKA (1)
6Secondary proton energy spectra from A-A collisions G4dpmjet2_5 & FLUKA (2) G4dpmjet2_5 following DPMJET-III here?Suggests at low-energy collisions, G4dpmjet2_5 over predicts (at least compared with FLUKA)?
8Status & future workG4dpmjet2_5 showing good consistency at high collision energies, but discrepancies at lower energies (~10GeV/nuc)No feedback yet on draft code … I’m not sure anyone has tried to use itFunctional and physics testing performed but more testing should be undertaken – critical to other MarsREM project deliverablesNeed to discuss with, e.g. Gunter, how to implement in G4 release, and once this is sorted, commit source to repositoryProton-nuclear and nuclear-proton interactionsAlready started DPMJET-III implementation (MarsREM)Extend Glauber profile data and Glauber inelastic cross-section data beyond A=58