Re: residual nuclei before/inside/after water target AND bragg curve]

Dear Erkan,
the shape of the fluka bragg peak is due to nucleus-nucleus interactions,
that remove part of the primary ion flux and generate fragments ranging
beyond the peak. If I'm not mistaken, trim does not take into account
nuclear inyteractions, and I guess that the G4 data were produced without
an ioni-ion interaction model. ..so it's not you that are missing
somenthing..
For spectra: here's an example of cards
* Theta/energy distribution of Heavy ions at Target entrance surface
USRBDX 101. HEAVYION -41. dump1 target Enter
USRBDX 100. 0.0 100. 10.&
* Theta /energy distribution of Heavy ions at Target exit surface
USRBDX 101. HEAVYION -42. target dump2 Exit
USRBDX 100. 0.0 100. 10.&
* theta distr. in entrance
USRYIELD 124. HEAVYION -43. dump1 target AngIn
USRYIELD 90. 0.0 10. 100. 0.0 3.&

The first two are double differential energy/angle. In the _sum.lis file
you get the total fluence as first thing, normalized in particle/primary
(would be particle/primary/cm^2 if one inputs the surface area in
what(6)). From the _tab.lis and from flair you can plot the energy
spectrum integrated over angle, in particles/GeV, or the double
differential in particles/GeV/steradiant

The usryield example scores angular distributions with a gate on kinetic
energy in the interval 0-100GeV (TOTAL, not per nucleon). The results are
given in particles/sr/GeV . NOTE the 1/GeV, even if it is only one
interval. To get the value "integrated over energy" you have to multiply
by the energy range, in this case 100 GeV.

Hope it helps
I would like again to encourage you to read the course transparencies and
the user manuual.
Paola

>
> Dear Paola
>
> thank you for your reply and comments
>
> for bragg-curve you are right that i missed that volume starts from 0.!
> so it is about 27 cm. but there are still some differences on the
> curves. while there is an instant drop at about 25cm for g4 and trim
> results, curve obtained by fluka looks like an exponential decay after
> that depth. and differences in entrance surface values. those can be
> from attached plots. what i missed here?
>
> and i want to create two below distribution for theta and energy of each
> individual species at target entrance/exit.
>
> 1. fluence (number of particle) vs. theta (degree)
> 2. fluence (number of particle) vs. energy (GeV/n)
>
> to obtain energy and angular distributions of fragments i tried usrbdx
> card (as can be seen in the input) however i could not manage that
> conversion thing you mentioned!
>
> could you give us some information about how to do these conversion with
> USRBDX and USRYIELD cards?
>
> meanwhile i liked the idea of AUXSCORE card.
>
> grazie mille
>
> ciao
> e.
>
>
>
>
> On Thu, 2009-06-18 at 10:32 +0200, Paola Sala wrote:
>>
>>
>> Dear Ercan,
>>
>> 1) If I'm not mistaken the water target and the usrbin both start
>> at z=10cm, therefore a bragg peak at z=37 cm means that its depth in
>> water is 37-10=27 cm (approx..)
>> 2) +3) +4 )you can use the USRBDX or the USRYIELD estimators. Both can
>> score particle current or fluence on a boundary. Tey are both
>> double-differential estimators, therefore you can also get the fragnents
>> angular distribution and spectra.
>> Be careful with normalizations!
>> Since the "heavyion" particle includes all ion species, you can select
>> the
>> isotope that you wish to score with the AUXCARD command.
>> You can have a look at the "scoring" lecture from the last fluka course
>> ( www.fluka.org --> courses-->athens-->program ) to have details, and of
>> course to the manual.
>> Hope this helps
>> Paola
>>
>> >
>> > dear all,
>> >
>> > i am trying to simulate nuclear fragmentations before/inside/after a
>> > water target.
>> >
>> > i attached my *.inp, *.flair, and mgdraw.for as well.
>> >
>> > i would like to be glad for any comments to those questions:
>> >
>> > 1. bragg curve does not cohorent to Geant4. with Fluka it is about
>> 37cm
>> > while 25cm with Geant4.
>> > what did i miss?
>> >
>> > 2. how to find an avarage number of each particles at entrance/exit
>> > surfaces of target?
>> >
>> > 3. how to find a distribution of each nuclear fragment deviation from
>> > beam direction (delta theta) at target entrance/exit surface?
>> > (frequency vs. theta [degree])
>> >
>> > 4. how to find an energy distribution of each nuclear fragmentation at
>> > target entrance/exit surface?
>> > (frequency vs. energy [MeV/n])
>> >
>> > thank you all
>> >
>> > ciao
>> > e.
>> >
>> >
>>
>>
>> Paola Sala
>> INFN Milano
>> tel. Milano +39-0250317374
>> tel. CERN +41-227679148
>>
>>
>> Paola Sala
>> INFN Milano
>> tel. Milano +39-0250317374
>> tel. CERN +41-227679148
>>
>

Paola Sala
INFN Milano
tel. Milano +39-0250317374
tel. CERN +41-227679148
Received on Fri Jun 19 2009 - 13:03:40 CEST