Dear Felicia,
> The number "stars," if I am not mistaken, is the number of all secondaries
> created in inelastic interactions?
no. A star is an inelastic interaction, so the number of stars is the
number of inelastic interactions (these do not include inelastic
interactions induced by neutrons below 20 MeV under the separate groupwise
treatment).
> I am looking for the number of only neutron secondaries that are created...
If you look at the table I indicated, you will find the number of neutrons
generated in inelastic interactions per beam particle. And in another
table above, you will also find the number of inelastic interactions
undergone by neutrons per beam particle. And in a third table, you will
even get the number of neutrons created by the mentioned <20 MeV neutrons,
whose number of interactions is printed too.
I think this info may serve your neutron multiplicity assessment purposes.
Note that, as an inelastic interaction takes place, it's rather
questionable to recognize among the products the old neutron.
Nevertheless, if you had one neutron and now you got two, your subtraction
algorithm gives indeed the number of additional neutrons.
Best wishes
Francesco
**************************************************
Francesco Cerutti
CERN-EN/STI
CH-1211 Geneva 23
Switzerland
tel. +41 22 7678962
On Fri, 30 Nov 2018, Felicia Sutanto wrote:
> Dear Francesco,
> Thank you for letting me know about the generation number (LTRACK). I really
> appreciate it.
>
> The number "stars," if I am not mistaken, is the number of all secondaries
> created in inelastic interactions?
> I am looking for the number of only neutron secondaries that are created...
>
> My apologies. I was not explaining my problem clearly. Let me try to explain
> it again an a hopefully clearer way.
> When a neutron undergoes inelastic scattering such as (n,xn) reaction, the
> old neutron is listed as one of the daughters.
> Since I am merely summing over the number of daughters that are created in
> every inelastic reaction, I am actually double counting these old neutrons.
>
> To avoid this double counting problem, I think for every (n,xn) reaction, I
> just need to subtract 1 from the number of daughters.
> Please let me know if you think this is the right way to properly count the
> number of neutron secondaries created per event.
>
> Thank you and best regards,
> Felicia
>
>
>
>
>
> On Fri, Nov 30, 2018 at 8:34 AM Francesco Cerutti
> <Francesco.Cerutti_at_cern.ch> wrote:
>
> Dear Felicia,
>
> note that the generation number you are printing (LTRACK) is the
> one of
> the parent particle inducing the reaction, not the one of the
> products you
> are listing (which is increased by one).
>
> At each inelastic interaction, the parent disappers and the
> produced
> particles are all 'new' and belonging to the next generation. So
> I'm not
> sure I fully understand your double counting concerns.
>
> Note also that in the output file you may already find what you
> are
> searching for, since - towards its end - there is a table giving
> the
> Number of secondaries generated in inelastic interactions
> [=stars] per
> beam particle
>
> Kind regards
>
> Francesco
>
> **************************************************
> Francesco Cerutti
> CERN-EN/STI
> CH-1211 Geneva 23
> Switzerland
> tel. +41 22 7678962
>
> On Wed, 28 Nov 2018, Felicia Sutanto wrote:
>
> > Hello FLUKA users,
> > I am a newbie and would really appreciate any help!
> > I am simulating fast neutrons interactions in a water
> detector.
> > My goal is to count all secondary neutrons created.
> >
> > Here is my current effort:
> > In mgdraw.f, I add the following in the USDRAW:
> > IF ( ICODE .EQ. 101 ) THEN
> > WRITE( IODRAW,* ) "# Inelastic coll at ", XSCO, YSCO, ZSCO
> > do 10 INP = 1, NP
> > WRITE( IODRAW,* ) usIn, TKI(INP), MREG, KPART(INP),
> > & CXR(INP),CYR(INP),CZR(INP),LTRACK, ICODE
> > 10 continue
> > END IF
> > Here is an example of an output for one event:
> >
> > (erg,region,pdgCode): (0.0614377,3,8) (Tx,Ty,Tz):
> (0.391015,0.00256892,-0.920381) (generation
> > no,interaction): (1,101)
> >
> > (erg,region,pdgCode): (0.0110293,3,1) (Tx,Ty,Tz):
> (0.450272,0.211508,-0.867479) (generation
> > no,interaction): (1,101)
> >
> > (erg,region,pdgCode): (0.00220192,3,8) (Tx,Ty,Tz):
> (0.058387,-0.934017,0.352425) (generation
> > no,interaction): (1,101)
> >
> > (erg,region,pdgCode): (0.00677268,3,1) (Tx,Ty,Tz):
> (-0.411252,0.366271,0.834696) (generation
> > no,interaction): (1,101)
> >
> > (erg,region,pdgCode): (0.00378545,3,7) (Tx,Ty,Tz):
> (-0.27657,-0.292502,0.915397) (generation
> > no,interaction): (1,101)
> >
> > (erg,region,pdgCode): (0.0026211,3,7) (Tx,Ty,Tz):
> (0.643253,-0.111001,0.757565) (generation
> > no,interaction): (1,101)
> >
> > (erg,region,pdgCode): (0.000197383,3,7) (Tx,Ty,Tz):
> (-0.20775,0.535758,-0.818415) (generation
> > no,interaction): (1,101)
> >
> > (erg,region,pdgCode): (0.0550734,3,8) (Tx,Ty,Tz):
> (0.400754,0.24182,-0.883696) (generation
> > no,interaction): (2,101)
> >
> > (erg,region,pdgCode): (0.00610732,3,7) (Tx,Ty,Tz):
> (-0.751712,0.657577,-0.050218) (generation
> > no,interaction): (2,101)
> >
> > (erg,region,pdgCode): (0.0266198,3,8) (Tx,Ty,Tz):
> (0.833339,-0.0743435,-0.54774) (generation
> > no,interaction): (3,101)
> >
> > (erg,region,pdgCode): (0.000992194,3,8) (Tx,Ty,Tz):
> (0.534859,0.646249,-0.544324) (generation
> > no,interaction): (3,101)
> >
> > (erg,region,pdgCode): (0.00150951,3,1) (Tx,Ty,Tz):
> (0.0855775,0.54351,0.835029) (generation
> > no,interaction): (3,101)
> >
> > (erg,region,pdgCode): (0.000419258,3,7) (Tx,Ty,Tz):
> (-0.934926,-0.0832789,-0.344932) (generation
> > no,interaction): (3,101)
> >
> > (erg,region,pdgCode): (0.0202234,3,8) (Tx,Ty,Tz):
> (0.808244,0.204056,-0.552361) (generation
> > no,interaction): (4,101)
> >
> > (erg,region,pdgCode): (0.00448876,3,7) (Tx,Ty,Tz):
> (0.0615197,0.334407,0.940419) (generation
> > no,interaction): (4,101)
> >
> > (erg,region,pdgCode): (0.00177942,3,7) (Tx,Ty,Tz):
> (0.943334,0.25021,-0.217983) (generation
> > no,interaction): (4,101)
> >
> > For each event, I count all neutrons that are produced
> (pdgCode = 8 = neutron). I then create a
> > histogram of the neutron multiplicity.
> >
> > The problem with this is that I double count these neutrons...
> > For example, the first two neutrons (highlighted in red) are
> the same parent neutron (generation no =
> > 1).
> > In Geant4, I can avoid double counting by knowing the trackID.
> > Is there a way to get "trackID" in FLUKA as well?
> > Apologies if the question is very obvious, I am still new to
> FLUKA..
> >
> > Thanks and best regards,
> > Felicia
> >
> >
>
>
>
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Received on Fri Nov 30 2018 - 20:25:52 CET