Interfacing the JQMD and JAM Nuclear Reaction Codes to

Geant4

Stanford Linear Accelerator Center

Koi, Tatsumi

tkoi@slac.stanford.edu

Collaboration withK. Niita (RIST) Y. Nara (University of Arizona)M. Asai (SLAC)D. H. Wright (SLAC)T. Sasaki (SLAC/KEK)K. Amako (KEK)

OutlineIntroducing joint activity of SLAC, KEK and other

institutes for interfacing Fortran code of JQMD and JAM to Geant4- To satisfy the urgent requirements for the beam test simulation of GLAST experiment.

ContentsWhat is JQMDWhat is JAMInterfacing Fortran reaction codes to Geant4DemonstrationSummary

We connected Fortran nuclear reaction codesto Geant4 which is written in C++.

Advantages of this method areThere are already many well-established reaction

codes and these codes are often written in Fortran.It is more convenient interfacing to Fortran code

directly than re-writing the code in C++.In the process of re-writing, new bugs may 　 enter into the code. We can avoid this situation.Once the interface is established, the Fortran　 　 code and Geant4 can be updated independently.No copyright problems associated with re-writes.

At the first stage of this activity we chose two reaction codes, which

satisfy our requirement(Nucleus-Nucleus Reactions)

Jaeri Quantum Molecular Dynamics (JQMD)

and Jet AA Microscopic Transport Model

(JAM)

JQMDQMD (Quantum Molecular Dynamics) is quantum extension of classical molecular-dynamics

model.QMD model is widely used to analyze various aspects of heavy ion reactions.JQMD ( Jaeri QMD) is a QMD code developed by JAERI ( Japan Atomic Energy Research Institute).JQMD includes SDM (Statistical Decay Model), SDM is

used for evaporation and fission decays of excited nuclei.

JQMD (cont.)Energy Range of JQMD

several 10 MeV/N up to about 3 GeV/NProjectile particle species

nuclei (including protons and neutrons) and pionsDetailed description of JQMD is given in Niita et al., Physical Review C 52 (1995) 2620 JQMD is also run within PHITS (Particle and Heavy-

Ion Transport code System). Iwase et al., Journal of Nuclear Science and

Technology 39 (2002) 1142

JAMJAM (Jet　AA　Microscopic　Transportation　Model) is

a hadronic cascade model.The trajectories of all hadrons as well as resonances

including produced particles are followed explicitly as a function of space and time.

The inelastic hadron-hadron collisions are described by resonance formation and decay at low energies (below ~4GeV). Above 4GeV string formation and fragmentation into hadrons is assumed.

Multiple minijet production is also included at high energies in the same way as the HIJING (Heavy Ion Jet INteraction Generator)

JAM (cont.)Energy Range of JAM

several 100 MeV/N up to about 100 GeV/Nand valid for many reactions at LHC and RHIC energies

Projectile particle speciesnuclei (including protons and neutrons)

mesons pions and kaonsDetailed description of JAM is given in Nara et al., Physical Review C 561 (1999) 4901

In order to use JQMD and JAM from Geant4,

we had to make interfaces.

Before discussing interfaces,it is useful to review Geant4

processes and how they handle hadronic interactions.

What Does a Process Do in Geant4

Decides when and where an interaction will occur (GetPhysicalInteractionLength)Cross section

Generates the final state (DoIt)Reaction model

What Does a Process Do in Geant4 (cont.)

ProcessGetCrossSection()

DoIt()

ModelApplyYoursel()

Cross Section

When and where

an interaction will occur?

What will be generated

by this interaction?

Hadron inelastic models ApplyYourself()

JQMD2G4InelasticModel::ApplyYourself()

or

JAM2G4InelasticModel ::ApplyYourself()

In this function,

Fortran JQMD or JAM routine is called.

G4HadronicProcessGetCrossSection()

PostStepDoIt()

G4HadronicDiscreteProcessGetCrossSection()

PostStepDoIt()

G4HadronicInteractonApplyYourSelf()

JQMD2G4InelasticModelApplyYourSelf()

Fortran JQMD routine

CrossSection

G4TriphathiJQMD2G4Shen

etc

Framework of Hadron Interactions

in Geant4

JAM2G4InelasticModelApplyYourSelf()

Fortran JAM routine

Cross Section for heavy ionsGetCrossSection()

Triphathi FormulaNASA Technical Paper 3621 (1997)G4TriphathiCrossSection

Shen FormulaNuclear Physics. A 491 (1989) 130JQMD2G4ShenCrossSection

Platforms used

Tested systemOS: Red Hat Linux 7.2 (6.2)Compiler: gcc-2.95.3 (2.91.66 with egcs-1.1.2)Geant4: Ver. 5.0.p01 (2003 Feb version.)

Demonstration System Cygwin 1.3.22-1 with gcc 3.2.3

We did not test this interface on other OS and compilers. Perhaps small modifications will be required.

Demonstrations N03HJQMD

Based on Geant4 novice exampleN03 N03HJAM

Based on Geant4 novice exampleN03 ICRU Sphere

International Commission on Radiation Units

Heavy ion passage in the tissue equivalent material

Simulation snapshot 1

Simulation snapshot 2

Simulation snapshot 3

Pion Plus from 17.5 GeV/c Proton on Be

I. Chemakin et al., Phys. Rev. C 65, 4904 (2002)

cos(θ)=0.75

cos(θ)=0.95

cos(θ)=0.65

cos(θ)=0.85

Pion from nucleus-nucleus interactions

Sugaya et al.,Nucl. Phys. A634, 115 (1998)

Pion from nucleus-nucleus interaction

Preliminary

Preliminary

Papp, LBL-3633, (1975)

Conclusions

We successfully developed the interface which connect JQMD and JAM to Geant4.

Hadronic framework of Geant4 proved its flexibility and expandability .

With this interface, we can simulate propagation of heavy ions in complex Geant4 geometries.

Preliminary test results agree well with data. Much more validation to be done.