Sanjay,
I have just noticed that you sent your last emails to me personally, and not
to the discussion list. Please keep the discussion on the list, otherwise
the other users cannot follow. I send my answer now to the list, and I hope that
the other users can reconstruct the discussion from what is recorded below.
Of course, since you did not give the detector volume (which was 100 cm3), the
program has assumed the volume was 1 cm3, and the results are too high by
a factor 100!
We have now 1.24e-05 photons/cm2/primary (analytical) and 1.68E-05 (FLUKA)
Same order of magnitude but there is still a difference.
Easy to explain: the photon tracks inside the Al slab are not all perpendicular
to the slab, but many are tilted and therefore longer than the perpendicular
ones. This can easily explain the 35% difference.
Alberto
On Tue, 4 Aug 2015, sanjay andola wrote:
> Thanks
> I have not given the detector volume in the usrtrk card, it will give right
> answer after dividing the volume if it is given in the card. is this logic
> is correct? sorry for the inconvenience.
>
> Sanjay
>
> On Tue, Aug 4, 2015 at 8:55 PM, sanjay andola <andolas.007_at_gmail.com> wrote:
>
>> It may not be. but if i take air attenuation negligible, then the after
>> 10 mm Al and isotropic X-ray source at 80cm from detector, the fluence
>> should be less than (1/4*pi*80*80) i.e. 1.24e-05 p/cm2/pr.
>>
>> t
>>
>> On Tue, Aug 4, 2015 at 8:46 PM, Fasso, Alberto <fasso_at_slac.stanford.edu>
>> wrote:
>>
>>> OK, this is much better. Now a question: you say "actual ones. which
>>> could be 1.24e-05 p/cm2/pr analyticaly?". Analytically how? How did you do
>>> the analytical calculation, and why do you think that the analytical result
>>> is "the actual one"?
>>>
>>>
>>> Alberto
>>>
>>>
>>> ------------------------------
>>> *From:* sanjay andola <andolas.007_at_gmail.com>
>>> *Sent:* Tuesday, August 4, 2015 8:11 AM
>>> *To:* Fasso, Alberto
>>> *Subject:* Re: [fluka-discuss]: Aluminium x ray transmission
>>>
>>> Thanks for the quick response.
>>> the USRTRK output (.lis) is attached in along with the email. Fluka
>>> output is 1.6764028E-03 0.3793046 % p/cmq/pr. the source is kept 80 cm
>>> from the detector volume.
>>>
>>> Thanks in advance
>>> Sanjay
>>>
>>> On Tue, Aug 4, 2015 at 7:59 PM, Fasso, Alberto <fasso_at_slac.stanford.edu>
>>> wrote:
>>>
>>>> I have written already many times and I would like all users to
>>>> understand that:
>>>>
>>>> A CALCULATION RESULT WITHOUT ITS STATISTICAL ERROR IS MEANINGLESS!!!!!
>>>>
>>>> We will not answer questions expressed without specifying errors.
>>>>
>>>>
>>>> Alberto
>>>> ------------------------------
>>>> *From:* owner-fluka-discuss_at_mi.infn.it <owner-fluka-discuss_at_mi.infn.it>
>>>> on behalf of sanjay andola <andolas.007_at_gmail.com>
>>>> *Sent:* Tuesday, August 4, 2015 5:36 AM
>>>> *To:* fluka-discuss_at_fluka.org
>>>> *Subject:* [fluka-discuss]: Aluminium x ray transmission
>>>>
>>>> Dear FLUKA experts,
>>>> I want to simulate the simple transmission of x-ray through different
>>>> thickness aluminium plates. in which USRTRK scoring i have used. the
>>>> results which I am getting from this is 1.6764028E-03 p/cmq/pr at 80 cm
>>>> distance from the source. 10 mm aluminium is placed in front of detector
>>>> volume. I am sending the input file also. why it is so different from
>>>> actual ones. which could be 1.24e-05 p/cm2/pr analyticaly. please elucidate
>>>> me.
>>>>
>>>> --
>>>> Sanjay Andola
>>>>
>>>
>>>
>
--
Alberto Fasso`
SLAC-RP, MS 48, 2575 Sand Hill Road, Menlo Park CA 94025
Phone: (1 650) 926 4762 Fax: (1 650) 926 3569
fasso_at_slac.stanford.edu
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Received on Tue Aug 04 2015 - 21:07:48 CEST