Problem 630

Summary: G4BinaryLightIonReaction missing recoil?
Product: Geant4 Reporter: corneliu
Component: processes/hadronic/modelsAssignee: Gunter.Folger
Status: RESOLVED FIXED    
Severity: normal    
Priority: P2    
Version: 6.1   
Hardware: PC   
OS: Linux   

Description corneliu 2004-06-01 11:41:40 CEST
Hi,
 Please excuse me if I am overlooking something here. The following is a snippet
from a v. simple simulation of a 1.85 GeV C-12 beam incident on a 1 x 1 cm^3
block of water;

AlongStepDoIt; particle loses 3.6 MeV to ionisation.
PostStepDoIt; an inelastic reaction occurs, modelled using G4BinaryLightIon,
resulting in a C-12 ion with kinetic energy 1.55 GeV.

Where is the missing 300 MeV? Assuming an elastic reaction or the reaction left
the target nucleus in an excited state, where is the recoiling target &/or
de-excitation products?

Best Regards,
Iwan

*********************************************************************************************************
* G4Track Information:   Particle = C12[0.0],   Track ID = 1,   Parent ID = 0
*********************************************************************************************************


Step#    X(mm)    Y(mm)    Z(mm) KinE(MeV)  dE(MeV) StepLeng TrackLeng
NextVolume ProcName
    0        0        0     -2.5  1.85e+03        0        0         0
World initStep


 >>AlongStepDoIt (after all invocations):
    ++List of invoked processes
      1) Transportation
      2) msc
      3) hLowEIoni


    ++G4Step Information
      Address of G4Track    : 0x8089660
      Step Length (mm)      : 0.317
      Energy Deposit (MeV)  : 6.5
      -----------------------------------------------------------------------
        StepPoint Information               PreStep            PostStep
      -----------------------------------------------------------------------
         Position - x (mm)   :                    0                   0
         Position - y (mm)   :                    0                   0
         Position - z (mm)   :                 -2.5               -2.18
         Global Time (ns)    :                    0             0.00206
         Local Time (ns)     :                    0             0.00206
         Proper Time (ns)    :                    0             0.00176
         Momentum Direct - x :                    0                   0
         Momentum Direct - y :                    0                   0
         Momentum Direct - z :                    1                   1
         Momentum - x (MeV/c):                    0                   0
         Momentum - y (MeV/c):                    0                   0
         Momentum - z (MeV/c):             6.69e+03            6.68e+03
         Total Energy (MeV)  :              1.3e+04             1.3e+04
         Kinetic Energy (MeV):             1.85e+03            1.84e+03
        Velocity (mm/ns)    :                  154                 154
         Volume Name         :                World               World
         Safety (mm)         :                    0               0.317
         Polarization - x    :                    0                   0
         Polarization - y    :                    0                   0
         Polarization - Z    :                    0                   0
         Weight              :                    1                   1
         Step Status         :            Undefined       PostStep Proc
         Process defined Step:            Undefined        IonInelastic
      -----------------------------------------------------------------------

    ++List of secondaries generated (x,y,z,kE,t,PID):  No. of secodaries = 0

 **PostStepDoIt (after all invocations):
    ++List of invoked processes
      1) Transportation
      2) msc
      3) IonInelastic (Forced)

    ++G4Step Information
      Address of G4Track    : 0x8089660
      Step Length (mm)      : 0.317
      Energy Deposit (MeV)  : 6.5
      -----------------------------------------------------------------------
        StepPoint Information               PreStep            PostStep
      -----------------------------------------------------------------------
         Position - x (mm)   :                    0                   0
         Position - y (mm)   :                    0                   0
         Position - z (mm)   :                 -2.5               -2.18
         Global Time (ns)    :                    0             0.00206
         Local Time (ns)     :                    0             0.00206
         Proper Time (ns)    :                    0             0.00176
         Momentum Direct - x :                    0           -0.000134
         Momentum Direct - y :                    0           -0.000576
         Momentum Direct - z :                    1                   1
         Momentum - x (MeV/c):                    0                  -0
         Momentum - y (MeV/c):                    0                  -0
         Momentum - z (MeV/c):             6.69e+03                   0
         Total Energy (MeV)  :              1.3e+04            1.12e+04
         Kinetic Energy (MeV):             1.85e+03                   0
         Velocity (mm/ns)    :                  154                   0
         Volume Name         :                World               World
         Safety (mm)         :                    0               0.317
         Polarization - x    :                    0                   0
         Polarization - y    :                    0                   0
         Polarization - Z    :                    0                   0
         Weight              :                    1                   1
         Step Status         :            Undefined       PostStep Proc
         Process defined Step:            Undefined        IonInelastic
      -----------------------------------------------------------------------

    ++List of secondaries generated (x,y,z,kE,t,PID):  No. of secodaries = 1
      [Note]Secondaries from AlongStepDoIt included.
              0         0     -2.18  1.55e+03   0.00206           C12[0.0]

#Step#    X(mm)    Y(mm)    Z(mm) KinE(MeV)  dE(MeV) StepLeng TrackLeng
NextVolume ProcName
    1        0        0    -2.18         0      6.5    0.317     0.317
World IonInelastic

*********************************************************************************************************
* G4Track Information:   Particle = C12[0.0],   Track ID = 2,   Parent ID = 1
*********************************************************************************************************

Step#    X(mm)    Y(mm)    Z(mm) KinE(MeV)  dE(MeV) StepLeng TrackLeng
NextVolume ProcName
    0        0        0    -2.18  1.55e+03        0        0         0
World initStep
Comment 1 Hans-Peter.Wellisch 2004-06-07 09:18:59 CEST
This is a very peculiar event, and I ahev a hard time to understand it. My
suspition is that the energy loss has changed the state of the ion, and hence
the hadronic final state generator just ignores it. But then this is just a
guess.

I think I'll need the source code to maker some progress on this one. Can you
be so kind to put it someplace where I can access it (including the macros to
run the job)?

Many greetings,

Hans-Peter.