Re: [VMC] VMC: hadronic interactions with ions

From: Ivana Hrivnacova (Ivana.Hrivnacova@cern.ch)
Date: Thu Dec 18 2003 - 13:51:55 MET


 Just to complete this;
 adding this functionality to VMC was required by Geant4
 VMC users; it is available from the version 1.1
 of Geant4 VMC.

 Best regards,

 Ivana

==============================================================
e-mail:  Ivana.Hrivnacova@cern.ch
address: Institut Physique Nucleaire, 91406 Orsay, France
phone:   (33) 01 69 15 65 94
==============================================================


On Thu, 18 Dec 2003, Federico Carminati wrote:

> Right,
>   what happens is fundamentally NOTHING, in the sense that GEANT3 does not 
> model hadronic interactions of ions *at all*. I am surprised you see any 
> hadronic interaction for everything with A>1. The latest version of FLUKA 
> handles ion interactions, but this is not yet completely interafaced with 
> the VMC. Fed
> 
> On Thu, 18 Dec 2003, Ivana Hrivnacova wrote:
> 
> > 
> >  Hi Paolo,
> > 
> >  I will only explain what does Geant3 VMC
> >  when you call gMC->DefineIon(..) in your
> >  VMC application class:
> > 
> >  gMC->DefineIon(...) adds a geant3 particle via 
> >  Gstpart(...) function with setting the ITRTYP code
> >  (type of tracking routine) to ITRTYP=8.
> >  Then this particle definition is also added to TDatabasePDG
> >  (if it does not yet exist here) and mapped to the geant3
> >  particle id.
> >  
> >  What happens next is a question for Geant3 experts.
> > 
> >  Regards,
> > 
> >  Ivana
> > 
> > ==============================================================
> > e-mail:  Ivana.Hrivnacova@cern.ch
> > address: Institut Physique Nucleaire, 91406 Orsay, France
> > phone:   (33) 01 69 15 65 94
> > ==============================================================
> > 
> > On Tue, 16 Dec 2003, paolo maestro wrote:
> > 
> > > Hi,
> > > I defined in the method AddParticles of my class
> > > inheriting from TVirtualMCApplication some ions through:
> > > 
> > > gMC->DefineIons("He4",2, 4, 2, 0, 3.75309);
> > > gMC->DefineIons("Li6",3, 6, 3,0 , 5.62963);
> > > gMC->DefineIons("B10",5, 10, 5,0 , 9.38272);
> > > and so on.
> > > Then I switched off the hadrons interaction in geant3
> > > by selecting  the FLUKA  generator.
> > > In my application I have a  calorimeter
> > > preceeded by a carbon target acting as a  pre-shower .
> > > I noticed that when I run with protons or nuclei as D, He up to Li6
> > > the hadronic cascades occur with a rate according to the total number of
> > > interaction
> > > lengths of my detector.
> > > But with heavier nuclei (starting from B10) the hadronic interactions
> > > seem to be switched off
> > > and nuclei pass through the calorimeter as minimum ionizing particles.
> > > The situation is even worse by using the geisha  generator. Infact in
> > > this case all the nuclei behave as mips.
> > > Which is the reason of these behaviours ?
> > > Is it due to some limitation of the fluka/geisha generator inside
> > > geant3?
> > > Or do I have to do something else to run properly with ions?
> > > Thanks.
> > > Best regards
> > >                     Paolo
> > > 
> > > 
> > > **************************
> > > Paolo Maestro
> > > Universita' di Siena-INFN
> > > Phone ++39-050-2214349
> > > Fax   ++39-050-2214317
> > > **************************
> > > 
> > > 
> > > 
> > 
> > 
> 
> 

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