Ion fragmentation in TVirtualMC

ROOT
1

Hi ROOT (and VMC) experts,
I have a working VMC application. It works fine when I use a beam of protons: I can see delta rays, energy losses and hadronic interactions (pion production) with all the three MCs.

If I define ions
gMC->DefineIon(“C12” , 6,12, 6, 78.01.e-09,12.000AMU);
…
and I try to use them as a beam ( fStack->PushTrack(toBeDone, -1, 1000060120, …) ),
as a result I could see the ion delta rays production and energy losses (propto Z2),
but I couldn’t be able to see any hadronic fragmentation.
This happens with all the three MCs.

This are my settings:
gMC->SetProcess(“HADR”,1);
gMC->SetCut(“CUTHAD”,1.0e-3);

What is the possible source of this problem?

Thank you,
Alberto

2

Dear Alberto,
please refer to the manuals of the transport MCs (Geant3, Geant4, Fluka) you want to use.
Geant3 does not perform hadronic heavy ion collisions.
For FLUKA and Geant4 you have to add these reactions to the physics lists.
In case of FLUKA you have to link to the DPMJET code and add

EVENTYPE 0. 0. 2. 0. 0. 0.DPMJET

  • The user requests transport of heavy ions with nuclear interactions

To the input cards.

Best regards - Andreas Morsch