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From: Chiriotti Alvarez Sabina <sabina.chiriotti.alvarez_at_sckcen.be>

Date: Fri, 9 Dec 2016 16:12:17 +0000

Dear Mikjail,

Thank you for the two routines.

I still have a question, with RACO function will it only generate particles outside the shell or it will sample the direction randomly?

Kind regards,

Sabina

From: Mikhail Polkovnikov <Михаил Полковников> [mailto:pmk_at_ihep.ru]

Sent: donderdag 8 december 2016 12:59

To: Chiriotti Alvarez Sabina; fluka-discuss_at_fluka.org

Subject: Re: [fluka-discuss]: sample discrete energies using SOURCE routine and surface source

On 08.12.2016 12:17, Chiriotti Alvarez Sabina wrote:

Dear Mikhail,

I would need a surface source sphere. The source should be like a shell around the target geometry of 5 um. Even if in the input it is written FLOOD it will not take into account no? At least this is what is written in FAQ.

How can I define this surface source?

Yes I have put the EMFCUT card higher than the maximum energy of the source because I would like to absorb all the electrons them at the point where are have been created.

Thank you for your help!

Kind regards,

Sabina

From: Mikhail Polkovnikov <Михаил Полковников> [mailto:pmk_at_ihep.ru]

Sent: donderdag 8 december 2016 7:51

To: Chiriotti Alvarez Sabina; fluka-discuss_at_fluka.org<mailto:fluka-discuss_at_fluka.org>

Subject: Re: [fluka-discuss]: sample discrete energies using SOURCE routine and surface source

On 07.12.2016 18:39, Chiriotti Alvarez Sabina wrote:

Dear FLUKA experts,

I have managed to sample the electron spectrum using the SOURCE routine.

Now I would like to have a surface source instead of the point source.

I read from the FAQ (http://www.fluka.org/fluka.php?id=faq&sub=4) that all settings defined with the beam card are ignored when using source routine. Therefore I have tried to use RACO routine as it is written in this message http://www.fluka.org/web_archive/earchive/prova/0954.html

Therefore I have added this part in the source routine:

* Particle coordinates

CALL RACO(TXX,TYY,TZZ)

RADIUS = 0.0005

XBEAM = RADIUS*TXX

YBEAM = RADIUS*TYY

ZBEAM = RADIUS*TZZ

XFLK (NPFLUKA) = XBEAM

YFLK (NPFLUKA) = YBEAM

ZFLK (NPFLUKA) = ZBEAM

However when I try run my simulation I got an error :

Region of particle in position -1.000000000E+30 -1.000000000E+30 -1.000000000E+30

cannot be determined, error count: 1

try again to establish the current region moving the particle of a 6.000000000E+18 long step

**** Particle in position X = -1.00000000E+30, Y = -1.00000000E+30, Z = -1.00000000E+30

**** with energy 0.000000E+00 GeV, discarded ****

If I remove CALL RACO(TXX,TYY,TZZ) the simulation works but it samples a point source.

Do I need to add something else when I call RACO routine? What I am doing wrong?

Thank you for your help.

Kind regards,

Sabina

From: Chiriotti Alvarez Sabina

Sent: vrijdag 25 november 2016 8:50

To: 'Vittorio Boccone'; fluka-discuss_at_fluka.org<mailto:fluka-discuss_at_fluka.org>

Subject: RE: [fluka-discuss]: sample discrete energies using SOURCE routine

Dear Vittorio,

thank you for your remarks. Yes the energies are spanned in 5 orders of magnitude and it corresponds to the Auger and IC electrons of I-125 Isotope (according to Howell 1992 Med Phys 19 (6). Then in order to simulate a decay I need to sample 26 electrons from this electron spectrum.

Therefore I am actually fine for your point 2 because I am using FLUKA for microdosimetry where I need to know how much energy is deposited locally for each decay.

How can I actually generate a source sample changing the weight of the primary particle (WTFLK) according to the probability associated to the energy?

thank you in advance.

kind regards,

Sabina

From: Vittorio Boccone [mailto:dr.vittorio.boccone_at_ieee.org]

Sent: donderdag 24 november 2016 20:41

To: Chiriotti Alvarez Sabina

Cc: fluka-discuss_at_fluka.org<mailto:fluka-discuss_at_fluka.org>

Subject: Re: [fluka-discuss]: sample discrete energies using SOURCE routine

Dear Sabina,

First. The spectrum you sent is not a histogram but a X/Y scattered plot with absolute probabilities (I attach the plot with your data). For this reason the cumulative sum will never work (statistically I mean). This has nothing to do with FLUKA. Clearly this is the cause of the discrepancy you mention between the 15 independent runs and the simulation with the “spectrum”.

Second. The transport for electrons in FLUKA starts at 1 keV -> 10e-6 GeV. Meaning a good fraction of the simulation will do essentially nothing else then depositing all the energy of the electron at the first interaction.

This will leave essentially a few meaningful points for your simulation, and would make me question whether you could really solve your problem this way.

Third. Supposed that you feel fine with what written in point2 2, you still have probabilities which span across 4 orders of magnitudes, therefore I could object if it would be better for you to generate a source sample changing the weight of the primary particle (WTFLK) according to the probability associated to the energy. Eventually you could separate the problem of determining the particle sample from the FLUKA simulation such you could verify it before running the simulation. In this case you could generate an external file from which the simulation would fetch energy and weight of the primary.

Best,

Vittorio

[imap://pmk_at_imap.ihep.ru:993/fetch%3EUID%3E/FLUKA%3E2748?header=quotebody&part=1.1.2&filename=image001.png]

On 24 Nov 2016, at 13:59, Chiriotti Alvarez Sabina <sabina.chiriotti.alvarez_at_sckcen.be<mailto:sabina.chiriotti.alvarez_at_sckcen.be>> wrote:

Dear FLUKA experts,

I would like to define an electron source which has a discrete energy spectrum (each bin of energy has a certain probability).

The sampling is done using a cumulative spectrum and interpolating between the discrete energies but

I have tried to do the sampling following the examples from FLUKA discussion list but I still do not get the same results if I do 15 independent simulations (the number for energies) and I combine the output with each electron probability. What I get is that the sampling is done with an interpolation between the discrete energies and I would like to simulate only the energies of the electron spectrum.

How can I remove the interpolation between discrete energies and sample the energies of the spectrum with their respective probability?

Please find in attachment the routine source, the spectrum and the input file.

Thank you in advance for your help.

Kind regards,

Sabina

-------------

Belgian Nuclear Research Centre, SCK-CEN

Environment, Health and Safety

Radiation protection, Dosimetry and Calibration

Boeretang 200,

2400, Mol, Belgium

tel: + 32 014 33 28 89

SCK•CEN Disclaimer: http://www.sckcen.be/en/e-mail_disclaimer <hsource.f><example.inp><Electron_spectrum.txt>

Dear Sabina,

You must set cosines as well. But in your input BEAMPOS card defines FLOOD (uniform and isotropic fluence within the sphere), while RACO is an isotropic distribution from the point source. What kind of distribution do you really need?

CALL RACO( TXX, TYY, TZZ)

* Cosines (tx,ty,tz)

TXFLK (NPFLKA) = TXX

TYFLK (NPFLKA) = TYY

TZFLK (NPFLKA) = TZZ

* Particle coordinates

XFLK (NPFLKA) = RADIUS * TXX

YFLK (NPFLKA) = RADIUS * TYY

ZFLK (NPFLKA) = RADIUS * TZZ

2. Transport and production thresholds (EMFCUT card) are higher than the maximum energy of your source!

Best regards,

Mikhail

Dear Sabina,

If you need a spherical shell source and your target will be exposed inside that shell, then you can use SFLOOD function. If you need isotropic distribution outside the spherical shell, then RACO function.

You can use any of these functions if you need just position coordinates X,Y,Z on the sphere for your "testsource" dump file.

When you use BEAMPOS card with FLOOD distribution, the RFLOOD variable from (BEAMCM) header contains the radius of the sphere and it can be used in the SOURCE user routine. There is no need to define RADIUS value once again.

There are two files in attachment with FLOOD and RACO functions for tests.

__________________________________________________________________________

You can manage unsubscription from this mailing list at https://www.fluka.org/fluka.php?id=acc_info

Received on Fri Dec 09 2016 - 19:39:45 CET

Date: Fri, 9 Dec 2016 16:12:17 +0000

Dear Mikjail,

Thank you for the two routines.

I still have a question, with RACO function will it only generate particles outside the shell or it will sample the direction randomly?

Kind regards,

Sabina

From: Mikhail Polkovnikov <Михаил Полковников> [mailto:pmk_at_ihep.ru]

Sent: donderdag 8 december 2016 12:59

To: Chiriotti Alvarez Sabina; fluka-discuss_at_fluka.org

Subject: Re: [fluka-discuss]: sample discrete energies using SOURCE routine and surface source

On 08.12.2016 12:17, Chiriotti Alvarez Sabina wrote:

Dear Mikhail,

I would need a surface source sphere. The source should be like a shell around the target geometry of 5 um. Even if in the input it is written FLOOD it will not take into account no? At least this is what is written in FAQ.

How can I define this surface source?

Yes I have put the EMFCUT card higher than the maximum energy of the source because I would like to absorb all the electrons them at the point where are have been created.

Thank you for your help!

Kind regards,

Sabina

From: Mikhail Polkovnikov <Михаил Полковников> [mailto:pmk_at_ihep.ru]

Sent: donderdag 8 december 2016 7:51

To: Chiriotti Alvarez Sabina; fluka-discuss_at_fluka.org<mailto:fluka-discuss_at_fluka.org>

Subject: Re: [fluka-discuss]: sample discrete energies using SOURCE routine and surface source

On 07.12.2016 18:39, Chiriotti Alvarez Sabina wrote:

Dear FLUKA experts,

I have managed to sample the electron spectrum using the SOURCE routine.

Now I would like to have a surface source instead of the point source.

I read from the FAQ (http://www.fluka.org/fluka.php?id=faq&sub=4) that all settings defined with the beam card are ignored when using source routine. Therefore I have tried to use RACO routine as it is written in this message http://www.fluka.org/web_archive/earchive/prova/0954.html

Therefore I have added this part in the source routine:

* Particle coordinates

CALL RACO(TXX,TYY,TZZ)

RADIUS = 0.0005

XBEAM = RADIUS*TXX

YBEAM = RADIUS*TYY

ZBEAM = RADIUS*TZZ

XFLK (NPFLUKA) = XBEAM

YFLK (NPFLUKA) = YBEAM

ZFLK (NPFLUKA) = ZBEAM

However when I try run my simulation I got an error :

Region of particle in position -1.000000000E+30 -1.000000000E+30 -1.000000000E+30

cannot be determined, error count: 1

try again to establish the current region moving the particle of a 6.000000000E+18 long step

**** Particle in position X = -1.00000000E+30, Y = -1.00000000E+30, Z = -1.00000000E+30

**** with energy 0.000000E+00 GeV, discarded ****

If I remove CALL RACO(TXX,TYY,TZZ) the simulation works but it samples a point source.

Do I need to add something else when I call RACO routine? What I am doing wrong?

Thank you for your help.

Kind regards,

Sabina

From: Chiriotti Alvarez Sabina

Sent: vrijdag 25 november 2016 8:50

To: 'Vittorio Boccone'; fluka-discuss_at_fluka.org<mailto:fluka-discuss_at_fluka.org>

Subject: RE: [fluka-discuss]: sample discrete energies using SOURCE routine

Dear Vittorio,

thank you for your remarks. Yes the energies are spanned in 5 orders of magnitude and it corresponds to the Auger and IC electrons of I-125 Isotope (according to Howell 1992 Med Phys 19 (6). Then in order to simulate a decay I need to sample 26 electrons from this electron spectrum.

Therefore I am actually fine for your point 2 because I am using FLUKA for microdosimetry where I need to know how much energy is deposited locally for each decay.

How can I actually generate a source sample changing the weight of the primary particle (WTFLK) according to the probability associated to the energy?

thank you in advance.

kind regards,

Sabina

From: Vittorio Boccone [mailto:dr.vittorio.boccone_at_ieee.org]

Sent: donderdag 24 november 2016 20:41

To: Chiriotti Alvarez Sabina

Cc: fluka-discuss_at_fluka.org<mailto:fluka-discuss_at_fluka.org>

Subject: Re: [fluka-discuss]: sample discrete energies using SOURCE routine

Dear Sabina,

First. The spectrum you sent is not a histogram but a X/Y scattered plot with absolute probabilities (I attach the plot with your data). For this reason the cumulative sum will never work (statistically I mean). This has nothing to do with FLUKA. Clearly this is the cause of the discrepancy you mention between the 15 independent runs and the simulation with the “spectrum”.

Second. The transport for electrons in FLUKA starts at 1 keV -> 10e-6 GeV. Meaning a good fraction of the simulation will do essentially nothing else then depositing all the energy of the electron at the first interaction.

This will leave essentially a few meaningful points for your simulation, and would make me question whether you could really solve your problem this way.

Third. Supposed that you feel fine with what written in point2 2, you still have probabilities which span across 4 orders of magnitudes, therefore I could object if it would be better for you to generate a source sample changing the weight of the primary particle (WTFLK) according to the probability associated to the energy. Eventually you could separate the problem of determining the particle sample from the FLUKA simulation such you could verify it before running the simulation. In this case you could generate an external file from which the simulation would fetch energy and weight of the primary.

Best,

Vittorio

[imap://pmk_at_imap.ihep.ru:993/fetch%3EUID%3E/FLUKA%3E2748?header=quotebody&part=1.1.2&filename=image001.png]

On 24 Nov 2016, at 13:59, Chiriotti Alvarez Sabina <sabina.chiriotti.alvarez_at_sckcen.be<mailto:sabina.chiriotti.alvarez_at_sckcen.be>> wrote:

Dear FLUKA experts,

I would like to define an electron source which has a discrete energy spectrum (each bin of energy has a certain probability).

The sampling is done using a cumulative spectrum and interpolating between the discrete energies but

I have tried to do the sampling following the examples from FLUKA discussion list but I still do not get the same results if I do 15 independent simulations (the number for energies) and I combine the output with each electron probability. What I get is that the sampling is done with an interpolation between the discrete energies and I would like to simulate only the energies of the electron spectrum.

How can I remove the interpolation between discrete energies and sample the energies of the spectrum with their respective probability?

Please find in attachment the routine source, the spectrum and the input file.

Thank you in advance for your help.

Kind regards,

Sabina

-------------

Belgian Nuclear Research Centre, SCK-CEN

Environment, Health and Safety

Radiation protection, Dosimetry and Calibration

Boeretang 200,

2400, Mol, Belgium

tel: + 32 014 33 28 89

SCK•CEN Disclaimer: http://www.sckcen.be/en/e-mail_disclaimer <hsource.f><example.inp><Electron_spectrum.txt>

Dear Sabina,

You must set cosines as well. But in your input BEAMPOS card defines FLOOD (uniform and isotropic fluence within the sphere), while RACO is an isotropic distribution from the point source. What kind of distribution do you really need?

CALL RACO( TXX, TYY, TZZ)

* Cosines (tx,ty,tz)

TXFLK (NPFLKA) = TXX

TYFLK (NPFLKA) = TYY

TZFLK (NPFLKA) = TZZ

* Particle coordinates

XFLK (NPFLKA) = RADIUS * TXX

YFLK (NPFLKA) = RADIUS * TYY

ZFLK (NPFLKA) = RADIUS * TZZ

2. Transport and production thresholds (EMFCUT card) are higher than the maximum energy of your source!

Best regards,

Mikhail

Dear Sabina,

If you need a spherical shell source and your target will be exposed inside that shell, then you can use SFLOOD function. If you need isotropic distribution outside the spherical shell, then RACO function.

You can use any of these functions if you need just position coordinates X,Y,Z on the sphere for your "testsource" dump file.

When you use BEAMPOS card with FLOOD distribution, the RFLOOD variable from (BEAMCM) header contains the radius of the sphere and it can be used in the SOURCE user routine. There is no need to define RADIUS value once again.

There are two files in attachment with FLOOD and RACO functions for tests.

__________________________________________________________________________

You can manage unsubscription from this mailing list at https://www.fluka.org/fluka.php?id=acc_info

(image/png attachment: image001.png)

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