Dear Mina
I am afraid it is not (yet) clear at all. Obviously for FLUKA DOSE is dose
that is energy/mass and it would be crazy to claim otherwise! Only for a
region scoring where the volume normalizations are generally unknown
to the code, FLUKA gives you energy/density/ASSUMED VOLUME=1 cm^3 which is
a nice way to say this is energy/density, I don't know the volume,
please apply it yourself.
It is to you as clearly explained in the manual and by Francesco to do the
final step, that is to divide by the region volume. There is no mistake
in the manual, no need for corrections, and contrary to your claim dose
for FLUKA is what it is for everybody as Francesco made already crystal
clear in his answer (which evidently was not clear enough).
Ciao
Alfredo
+----------------------------------------------------------------------+
| Alfredo Ferrari || Tel.: +41.22.76.76119 |
| CERN-EN/STI || Fax.: +41.22.76.69474 |
| 1211 Geneva 23 || e-mail: Alfredo.Ferrari_at_cern.ch |
| Switzerland || |
+----------------------------------------------------------------------+
On Thu, 27 Feb 2014, Mina Nozar wrote:
> Dear Francesco,
>
> Yes, this makes it clear and I appreciate your explanation, THANK YOU. The
> key point is that the FLUKA quantity scored as DOSE is not the standard
> definition of DOSE.
>
> FLUKA's quantity scored as DOSE: Energy/density
> Standard def. of DOSE: Energy/mass
>
> Can your explanation please be added to the manual for the future release?
>
> Cheers,
> Mina
>
>
> On 14-02-27 02:20 PM, Francesco Cerutti wrote:
>>
>> Dear Mina,
>>
>> deposited energy and absorbed dose are evidently related, one could even
>> dare to say that basically they are the same thing, just differently
>> normalized. But I think you are overlooking a basic aspect: actually the
>> strict relationship is between deposited energy *density* and dose. Let's
>> consider that with a regular USRBIN mesh you get a local value and with a
>> USRBIN per region you get a global value. In case of ENERGY, this will
>> yield local energy density [GeV/cm3] and total (or integrated) energy
>> [GeV], respectively. Note that these are two different quantities, as
>> their units demonstrate, and both are well defined and meaningful, because
>> energy is an extensive quantity, increasing with volume (or with
>> mass=volume*density). Instead in case of DOSE, calculated by FLUKA as
>> ENERGY/density, you will have local dose [GeV/g] and average dose times
>> volume [GeV/(g/cm3)], respectively. The second quantity is not a dose,
>> since a total (or integrated) dose does not make sense! And you have to
>> divide it - divide, not multiply - by the region volume in order to get
>> back the dose averaged over the region.
>> So you can happily compare the SCOREd ENERGY ([GeV], with no input volume)
>> divided by the region mass (volume*density) - this way getting the average
>> dose - to the USRBIN (per region) DOSE divided by the region volume. But
>> you cannot call "dose" the value produced by the USRBIN per region, being
>> the latter an odd quantity unless you divide it by the region volume.
>>
>> As you will score, e.g., PROTON, regular USRBIN on one side and USRBIN per
>> region and SCORE on the other will yield you fluence [cm-2] and
>> tracklength [cm], respectively. Here again two different and meaningful
>> quantities.
>>
>> Hope this helps
>>
>> Francesco
>>
>> **************************************************
>> Francesco Cerutti
>> CERN-EN/STI
>> CH-1211 Geneva 23
>> Switzerland
>> tel. ++41 22 7678962
>> fax ++41 22 7668854
>>
>> On Thu, 27 Feb 2014, Mina Nozar wrote:
>>
>> > Hello Francesco,
>> >
>> >
>> > I completely understand the difference B/N 'binning' and 'region'
>> > definition in USRBIN (or at least I think I do). In the 'binning'
>> > case, quantities scored are given as /cm3*primary but for 'region' case,
>> > the quantities are given over the volume of the region (so
>> > integrated/total values).
>> >
>> > The manual, under USRBIN, note 5 says:
>> >
>> > 5. Energy deposition will be expressed in GeV per cm3 per unit primary
>> > weight.
>> > Doses will be expressed in GeV/g per unit primary weight. To obtain
>> > dose in Gy, multiply GeV/g by 1:602176462 10E7.
>> >
>> > Why is the unit for the the Dose scored as the quantity, not GeV/g/cm3
>> > here??? This is inconsistent with note 13:
>> > "The results from USRBIN are normalised per unit volume and per unit
>> > primary weight, except for region binnings and special user-dened
>> > binnings, which are normalised per unit primary weight only"
>> >
>> > ----------------------------------------------------------------
>> >
>> > The forum links you have sent, say in USRBIN region binning, the units
>> > are GeV/[g/cm3] when one scores Dose and has to multiply to results by
>> > the volume to get the actual dose [GeV/g]. Fine, but this should be
>> > added to the manual.
>> >
>> > We used SCORING through score as a cross-check of the USRBIN Region
>> > binning results.
>> > Can we compare (non-normalized values) from SCORE for deposited energy
>> > to Dose from USRBIN region binning, scoring Dose, by dividing the dep.
>> > energy values in through SCORE by the mass of the region???
>> > I guess the question is whether deposited energy and absorbed dose are
>> > related.
>> >
>> > Thank you in advance,
>> > Mina
>> >
>> > On 14-02-27 02:02 AM, Francesco Cerutti wrote:
>> > >
>> > > Hallo Mina & Martin,
>> > >
>> > > you do not need to send your inputs, your expectations concerning
>> > > USRBIN
>> > > per region are wrong, not complying with what is written in the
>> > > manual
>> > > (USRBIN, Note 13) and with what has been already explained in this
>> > > forum
>> > > (http://www.fluka.org/web_archive/earchive/new-fluka-discuss/4288.html,
>> > >
>> > > http://www.fluka.org/web_archive/earchive/new-fluka-discuss/3458.html).
>> > >
>> > >
>> > > Once more: FLUKA does not know region volumes, so values per region
>> > > cannot
>> > > be normalized per region volume. If you ask for ENERGY, you will get
>> > > GeV
>> > > (per primary) and not GeV/cm3, if you ask for DOSE you will get the
>> > > same
>> > > as before divided by the material density (i.e. GeV/(g/cm3) and not
>> > > GeV/g).
>> > >
>> > > (Only) SCORE values can be normalized by region volumes provided that
>> > > one
>> > > inputs them (though the practical benefit of that is quite
>> > > questionable -
>> > > I'm not aware of anybody using it -, since one can always renormalize
>> > > SCORE values at postprocessing level; all this still assuming that
>> > > people
>> > > actually use values from SCORE, which is an historical scoring option
>> > > not
>> > > supporting automatic statistical analysis). If not, a default value
>> > > of
>> > > 1cm3 is used for normalization purposes as you noticed, meaning
>> > > that the
>> > > SCORE value for ENERGY should be intended as GeV, contrary to your
>> > > conclusions and according to what is in the manual (SCORE, Note 4).
>> > >
>> > > Coming now to your case 2b, if you follow the manual and set IVLFLG =
>> > > 3 in
>> > > the geometry title card and write the volumes (in fixed format: 10
>> > > fields
>> > > per region, 7 regions per row) before the GEOEND card (after the
>> > > region
>> > > END card), everything works as expected: the SCORE values will get
>> > > normalized by your volumes and the latter ones will appear in the
>> > > volume
>> > > column. You still got default volume values of 1cm3 due to a Flair
>> > > bug,
>> > > not translating correctly what was input in the region metacard under
>> > > the
>> > > Volume label. This is going to be fixed in the next Flair version (by
>> > > the
>> > > way, Flair 2 is coming!), but it gives me the nasty opportunity to
>> > > remind
>> > > people that in case of problems and unexpected behaviors one should
>> > > look
>> > > at the input file as actually fed to FLUKA, leaving for a little while
>> > > the
>> > > wonderful Flair world and using a trivial text editor to inspect what
>> > > is
>> > > underneath.
>> > >
>> > > Best wishes
>> > >
>> > > Francesco
>> > >
>> > > **************************************************
>> > > Francesco Cerutti
>> > > CERN-EN/STI
>> > > CH-1211 Geneva 23
>> > > Switzerland
>> > > tel. ++41 22 7678962
>> > > fax ++41 22 7668854
>> > >
>> > > On Thu, 27 Feb 2014, Mina Nozar wrote:
>> > >
>> > > > Hello everyone,
>> > > > > We are trying to score Absorbed Dose in a given region. We
>> > > have tried > two scoring methods:
>> > > > 1) via a USRBIN card with REGION binning and DOSE as the quantity
>> > > scored
>> > > > and
>> > > > 2) via a SCORE card and Energy as the quantity scored, with no
>> > > volume > input (case 2a) and with volume input (case 2b).
>> > > > > According to the manual, we should get
>> > > > - GeV/g per primary for option 1
>> > > > - GeV per primary for option 2a
>> > > > - GeV/cm3 per primary for option 2b
>> > > > > > As for the volume setting for the SCORE card, we set IVFLG to
>> > > 3 in the > GEOBIN title card and inputted the region volume in the
>> > > geometry region > card for the region.
>> > > > > > We are seeing some discrepancies. The value we get from
>> > > SCORE (with no > volume setting, case 2a) agrees with the value from
>> > > the USRBIN, if we > divide the SCORE value by the density. This
>> > > implies that the SCORE > value is GeV/cm3 per primary which doesn't
>> > > agree with what is in the > manual.
>> > > > > Furthermore, when we do set the volume, following the
>> > > instructions > above, we still see a value of 1.000000000D+00 for the
>> > > region's volume > and the same deposited energy value as in case 2a.
>> > > > > This is a source of confusion for us and we are eager to find
>> > > whether we > are missing something. Can someone shed some light on
>> > > this please?
>> > > > Is there another way to score absorbed dose in a region?
>> > > > > Thank you very much,
>> > > > Mina & Martin
>> > > > >
>> >
>> >
>> >
>>
>
>
Received on Fri Feb 28 2014 - 08:50:32 CET