RE: [fluka-discuss]: track length and energy deposition of fission fragments

From: Francesco Cerutti <Francesco.Cerutti_at_cern.ch>
Date: Tue, 9 May 2017 18:47:47 +0200

Hi

to inspect single tracks and respective energy deposition along them, I'd
stay with mgdraw, just moving to the top of it, where this information
- referring to the particle being currently transported, including ions -
can be retrieved. You may want to look at chapter 11 in the manual.
Moreover, the ENTRY ENDRAW allows to incercept 'point' energy deposition.

However, pay attention to the fact that only the fraction of energy
deposition related to nuclear stopping power is physically linked to
lattice disorder generation. What depends on electronic stopping power
(largely dominant except at pretty low energies) goes to electrons and
does not induce lattice displacements. Your heavy fragments are certainly
slow and pertain to an energy range where nuclear stopping power may carry
a not negligible contribution to the energy deposition value, but off-line
disentangling is not an immediate task (while in the code, for DPA and
NIEL calculation purposes, it is automatically done).

Best

Francesco

**************************************************
Francesco Cerutti
CERN-EN/STI
CH-1211 Geneva 23
Switzerland
tel. ++41 22 7678962
fax ++41 22 7668854

On Tue, 9 May 2017, Cristina Martin Perez wrote:

> Dear Francesco,
>
> Thank you for your suggestions.
>
> I have already performed the DPA study and got the results that I expected, but I would like to look deeper into the fission fragments length and energy deposition distributions. Is there any way to intercept heavy fragments (or other secondaries) during their transport and retrieve this information? Would the comscw.f routine be a good approach? (I have started trying it, but I always get RULL=1.0, which I suspect is the weight associated to the energy deposition, but not the amount itself?).
>
> Thanks again!
>
> Best regards,
> Cristina
> ________________________________________
> From: Francesco Cerutti
> Sent: Tuesday, May 09, 2017 15:38
> To: Cristina Martin Perez
> Cc: FLUKA discussion
> Subject: Re: [fluka-discuss]: track length and energy deposition of fission fragments
>
> Dear Cristina,
>
> in USDRAW your intercept your heavy fragments when they are generated, not
> during their transport, which a track length is associated to.
>
> To your purposes (damage, lattice disorder study), there is a much more
> direct and proper way to proceed, that is calculation of DPAs (it has been
> implemented in the code exactly to those purposes). You shall score
> DPA-SCO with USRBIN, after activating ion transport and lowering hadron
> thresholds as much as possible (as I explained last week). This way, also
> the DPA contribution of low energy neutron products - not generated
> explicitly - is taken into account. You will eventually get a spatial DPA
> distribution, giving a picture of damage distribution and level.
>
> Cheers
>
> Francesco
>
> **************************************************
> Francesco Cerutti
> CERN-EN/STI
> CH-1211 Geneva 23
> Switzerland
> tel. ++41 22 7678962
> fax ++41 22 7668854
>
> On Tue, 9 May 2017, Cristina Martin Perez wrote:
>
>> Dear FLUKA experts,
>>
>> I am running a simulation where I irradiate a PbWO4 crystal with protons to understand the
>> hadron damage produced. The features of the experimentally observed damage hint at lattice
>> disorder that might be caused by fragments of heavy elements that have a very short track
>> length and a high energy deposition in the crystal. Therefore, I am trying to retrieve the
>> length track and energy deposition of the heavy fission fragments with the mgdraw.f user
>> routine, entry USRDRAW. Find attached my mgdraw.f file and the output file
>> (pwo_fragments001_fort.44) I get.
>>
>> I obtain the information of the heavy fragments produced after each interaction the following
>> way:
>>
>> do 20 ip = 1, NPHEAV
>>
>> WRITE( 44.0, '(A2,I5.5,1X,I3,1X,A2,1X,I2,1X,I2,
>> &1X,F10.6,1X,F10.6,1X,F10.6,1X,F10.6,1X,I2,1X,I2,1X,I2,1X,I2,1X,
>> &F10.6,1X,F10.6,1X,F10.6)')'H ',NCASE,ICODE,'-',ip,KHEAVY(ip),
>> &TKHEAV(ip)+AMNHEA(KHEAVY(ip)),CXHEAV(ip),
>> &CYHEAV(ip),CZHEAV(ip),NTRACK,MTRACK,ICHEAV(KHEAVY(ip)),
>> &IBHEAV(KHEAVY(ip)),AMNHEA(KHEAVY(ip))
>>
>> 20 continue
>>
>> and I get an output of the type:
>>
>> H 00001 101 - 1 6 3.738171 -0.910575 -0.127528 0.393178 0 0 2 4 3.727380
>>
>> i.e. NTRACK=0 and MTRACK=0. From the manual, I understand this means that the energy
>> deposition is point-like, so it's not recorded in (TRACKR). I have seen other methods to get
>> the energy deposition, but I see some problems and I wonder which one would suit best my
>> goals:
>>
>> (1) Scoring the energy deposition with USRBIN, using AUXSCORE to filter the heavy fragments:
>> this way I cannot identify what energy deposit belongs to what fragment, right?
>>
>> (2) Using the comscw.f routine: I could get the generalized particle id (IJ), the deposited
>> energy (RULL) and the particle generation (LLO), but how do I know the ID in the case of the
>> heavy fragments? Should I just add the (FHEAVY) include file and get the information from
>> there?
>>
>> I would really appreciate if you could give me a hint as to what path to follow for my study.
>>
>> Best regards,
>> Cristina
>>
>>
>

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Received on Tue May 09 2017 - 20:08:56 CEST

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