Pete Truscott QinetiQ Space LoB DPMJET-II.5 and DPMJET-III Implementation in Geant4 Overview & Status Report Pete Truscott QinetiQ Space LoB 03 July 2008

Implementation 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/nuc applicable to all projectiles & targets Poorly 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 blocks Geant4 DPMJET-II.5 interface: G4DPMJET2_5Model class now developed and under test After 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 parameter For 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 = 58 It 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)

Implementation of DPMJET-II.5 model in Geant4 (2) Total inelastic cross-sections Total 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 Compatibility Tested 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 v3.2.3 gcc v4.0.0 with g77 v3.2.3 gcc v4.2.0 with gfortran v4.2.0 gcc v4.2.3 with gfortran v4.2.3 WARNING: 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.

Implementation of DPMJET-II.5 model in Geant4 (3) Use in physics list G4ExcitationHandler *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 compilation Instructions in software manual on how to install & build G4dpmjet2_5, and modifications required to user’s GNUmakefile

Secondary proton energy spectra from A-A collisions G4dpmjet2_5 & FLUKA (1)

Secondary 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)?

Secondary proton &  rapidity spectra from A-A collisions G4dpmjet2_5 & experiment Shows underprediction Proton 

Status & future work G4dpmjet2_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 it Functional and physics testing performed but more testing should be undertaken – critical to other MarsREM project deliverables Need to discuss with, e.g. Gunter, how to implement in G4 release, and once this is sorted, commit source to repository Proton-nuclear and nuclear-proton interactions Already started DPMJET-III implementation (MarsREM) Extend Glauber profile data and Glauber inelastic cross-section data beyond A=58

Backup Slides

G4dDPMJET2_5Model logical flow

Summary of G4DPMJET2_5Model classes

G4dDPMJET2_5CrossSection logical flow