Thank you very much.
Regards,
Raksha.
----- Original Message -----
From: "paola sala" <paola.sala_at_mi.infn.it>
To: "Raksha Rajput" <rakshak_at_britatom.gov.in>
Cc: "paola sala" <paola.sala_at_mi.infn.it>, fluka-discuss_at_fluka.org
Sent: Tuesday, August 11, 2020 4:11:38 PM
Subject: Re: [fluka-discuss]: Surface dose rate calculations
Hello
the lowest possible threshold is 1 keV, but the threshold set with the
PRECISION defaults is 100keV.
To go lower, one has to issue EMFCUT cards, both for production
(sdum=PROD-CUT) and transport (blank SDUM).
Threshold values can be checked by looking at the output file
Regards
Paola
> Am sorry, the photon energy in my case is 36 keV, please note, it was
> typed wrongly as 0.036 keV.
> Thanks,
> Raksha.
>
> ----- Original Message -----
> From: "Raksha Rajput" <rakshak_at_britatom.gov.in>
> To: "paola sala" <paola.sala_at_mi.infn.it>
> Cc: fluka-discuss_at_fluka.org
> Sent: Monday, August 10, 2020 10:02:35 PM
> Subject: Re: [fluka-discuss]: Surface dose rate calculations
>
> Dear Expert,
> That's so kind of you, thank you.
>
> One more ques please: For the same geometry, I wish to score Dose Eq with
> a photon energy 0.036 keV, but I am getting 0.00E+00 for primaries as high
> as 8E07, 20 cycles, 2 spawns. I noticed in the manual that the lowest
> energy of primary photon should not be less than 1 keV (mine is higher
> than that ).
> Kindly suggest some improvements so that I get an answer for low energy
> photons of 0.036 keV, 0.0215 keV etc... Am I missing something ?
>
> Thanks and regards,
> Raksha Rajput.
>
> ----- Original Message -----
> From: "paola sala" <paola.sala_at_mi.infn.it>
> To: "Raksha Rajput" <rakshak_at_britatom.gov.in>
> Cc: "paola sala" <paola.sala_at_mi.infn.it>, fluka-discuss_at_fluka.org
> Sent: Sunday, August 9, 2020 7:03:05 PM
> Subject: Re: [fluka-discuss]: Surface dose rate calculations
>
> Hi
> Sorry I mis-red the position of the source.
> Yes, if it is at x different from zero the symmetry is broken.
> I would say that the two approaches you mention are equivalent
> And, again, my sentence about solid angle was wrongly assuming a source on
> the z axis.
> Apologies
> Paola
>
>>
>>
>>
>> From: "paola sala" <paola.sala_at_mi.infn.it>
>> To: "Raksha Rajput" <rakshak_at_britatom.gov.in>
>> Cc: fluka-discuss_at_fluka.org
>> Sent: Friday, August 7, 2020 8:04:59 PM
>> Subject: Re: [fluka-discuss]: Surface dose rate calculations
>>
>> Hello
>> given that your geometry is cylindrically symmetric, I would suggest a
>> cylindrical binning.
>> Okay, noted.
>>
>> And, I do not see the need to have more than one bin in phi. Again, the
>> geometry is phi-symmetric and the source is on the axis of the cylinder,
>> there cannot be any phi-dependence in the results except for statistical
>> fluctuations, and you'll gain a lot of statistics integrating over 2pi
>> in
>> phi.
>> But if the source is placed at (4.6,0,0), the dose-Eq at x=
>> -5.0445,y=0,z=0 will be different from that at x= +5.0445,y=0,z=0. Does
>> this not imply the dependence of dose -eq on phi ? As I understand, phi
>> varies from 0 to pi, from +X to-X via +Y and phi varies from 0 to -pi,
>> from +X to -X via -Y. Hence the values are listed from -pi to +pi and I
>> pick the bin value numbered 180th and 181st (from 360 bin values) to get
>> the dose-Eq at x=+5.0445,y=0,z=0 (that is phi = 0.01744 rad and phi = -
>> 0.01744 rad). Am I missing some point ?
>>
>> Then: do you want to score dose or dose-eq? I see two different
>> quantities
>> in the output files.
>> Scored Dose-Eq. ('Dose' was written by mistake in SDUM, in one of the
>> files).
>>
>> About the difference in statistics: if you score at z=0 in both cases,
>> the solid angle will be different for the two cases, thus the statistics
>> will be different.
>> Thank you .
>>
>> Regards
>> Paola
>> Kindly clarify a little more. Thanks and regards,
>> Raksha.
>>
>>
>>
>> Dear Experts,
>>
>> We have tried to calculate maximum surface dose rate on the surface of a
>> SS cup (with center at (0,0,0) and outer radius 5.0445 cm) when the
>> source
>> is at (4.6,0,0).
>>
>> We tried this with Cartesian binning and R-phi-Z binning and scored
>> DOSE-EQ.
>>
>> Please find attached the input files for 765.8 keV photon for both type
>> of
>> binnings and the results obtained (.lis fles).
>>
>> We would request you to comment on the correctness of the input and the
>> results obtained.
>>
>> Can you please suggest which of the two binnings is advisable in our
>> case
>> ? Or, both can be used ?
>>
>> As we needed the dose rate at a point, we have reduced the volume of the
>> bin to 1 mm^3 approx. - is this okay as the statistical errors seem less
>> ?
>> (We also found that when the source is at (0,0,0), the statistical
>> errors
>> seem to increase for 1 mm^3 binning detector, when compared to source at
>> (4.6,0,0). We couldn't understand why. Please throw some light on this.
>> )
>>
>> Kindly suggest any improvement to evaluate the dose rate at a point
>> using
>> FLUKA.
>>
>> Can you provide some example of using "special user defined 3D binning"
>> in
>> USRBIN ?
>>
>> Thanks and regards,
>> Raksha Rajput.
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> Paola Sala
>> INFN Milano
>> tel. Milano +39-0250317374
>> tel. CERN +41-227679148
>>
>>
>
>
> Paola Sala
> INFN Milano
> tel. Milano +39-0250317374
> tel. CERN +41-227679148
>
>
> __________________________________________________________________________
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>
Paola Sala
INFN Milano
tel. Milano +39-0250317374
tel. CERN +41-227679148
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Received on Thu Aug 13 2020 - 12:45:06 CEST