[VMC] Re: VMC: hadronic interactions with ions

From: Paolo MAESTRO (paolo.maestro@pi.infn.it)
Date: Thu Dec 18 2003 - 17:47:01 MET


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.
> 
>  

Maybe I misinterpreted the output of my simulation  but
 you may find he verbose output of two different events my program 

produced at the following address

http://www.pi.infn.it/~maestro/vmc

In both the cases , a He4 nuclei is generated above the carbon pre-shower target.
In event1.txt  the He4 undergoes a  hadronic inelastic process in the target and
then pions , kaons neutron, protons, deuterons are produced.
In event2.txt the primary nucleon passes through the detector without 
hadronic inelastic interactions.
Which is your explanation?

>  
> The latest version of FLUKA
> handles ion interactions, but this is not yet completely interafaced with
> the VMC. Fed

 
When do you think a first public release of the fluka-VMC interface will be ready
and available ?
Is there some "beta" version one can already use ?
Many thanks.

Best  regards
                              Paolo
 
> > 
> > >
> > > 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
> > > > > **************************
> > > > >
> > > > >
> > > > >
> > > >
> > > >
> > >
> > > --
> > >
> > >                                             Federico Carminati
> > >
> > > ==============================================================================
> > > || Federico Carminati             ||  Telephone : +41.22.767.4959           ||
> > > || CERN-EP                        ||  Fax       : +41.22.767.9480           ||
> > > || 1211 Geneva 23                 ||  Mobile    : +41.79.201.4843           ||
> > > || Switzerland                    ||                                        ||
> > > ==============================================================================
> > 
> > --
> > **************************
> > Paolo Maestro
> > Universita' di Siena-INFN
> > Phone ++39-050-2214349
> > Fax   ++39-050-2214317
> > **************************
> > 
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