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From: Anna Ferrari <a.ferrari_at_hzdr.de>

Date: Mon, 02 Sep 2013 00:31:43 +0200

Dear Jonathan,

first of all, maybe it is useful to remember that the distinction between

photon and electron dose does not make sense in reality, because also in the

case of photons the dose is always entirely due to the secondary electrons

that they produce.

When with FLUKA you calculate the DOSE (the energy deposited per unit mass)

due to the photons, you see the effect of the transport threshold that

"forces" the photon below threshold to locally deposit his energy.

When on the other hand you calculate the DOSE-EQ (dose equivalent) due to the

photons, you fold the photon fluence with a set of conversion coefficients

that have been calculated on a proper phantom where, another time, the dose

was entirely due to the secondary electrons produced by photons.

The second thing that it is useful to clarify is that when you compute with

USRBIN a DOSE or a DOSE-EQ (in the second case by selecting the desired set of

conversion coefficient via the AUXSCORE card), you get by default all the

contributions coming from all the particles generated by your primary beam. If

you want to filter the contribution of a certain kind of particles you have to

declare it in the AUXSCORE card.

Coming to your questions, in 1) and 2) there is a bit of confusion between

ambient dose equivalent H*(10), personal dose equivalent Hp(10), effective

dose and sets of conversion coefficients from fluence to dose

equivalent/effective dose. I would suggest to look at this lecture (p. 14-16):

https://www.fluka.org/free_download/course/nea2013/Lectures/18_Activation.pdf

where you can find also a useful reference.

I would summarize that in FLUKA for your needs you can find:

- for ambient dose equivalent calculations: the conversion coefficients

fluence/H*(10), based on ICRP74 values (and values calculated by M.Pelliccioni

for neutrons above 20 MeV).

You explicitly select it via AUXSCORE with sdum=AMB74 (in any case this is the

default choice, you get it by selecting the DOSE-EQ scoring also without

giving the option AUXSCORE).

As said above, by default you get all the contributions to the H*(10).

- for effective dose calculations: conversion coefficients fluence/effective

dose.

They are implemented for three different irradiation geometries (please see

manual and lecture cited above).

The choice sdum=ETW74 selects the coefficients there are obtained by

considering, for each energy bin in each data set corresponding to a certain

kind of particle, the maximum coefficient of anterior posterior, posterior

anterior, right lateral and left lateral geometries.

This set of coefficients is therefore always conservative with respect to the

effective dose (which depends on the irradiation geometry). It is a very good

choice for shielding purposes.

...and now, let's start from the question 1:

1) " If I use USRBIN-DOSE-EQ is it the same as h*(10) (photon ambient dose

only)? Moreover, is it the same as USRBIN with tracking photon and a AUXCORE

card with a routine AMB74? "

No. If you use a USRBIN with what(2)=DOSE-EQ by default you get H*(10) with

all the contributions to the dose equivalent. If you want to isolate the

contribution coming from the photon fluence you have to filter it via

AUXSCORE.

Moreover: a USRBIN with what(2)= PHOTON select the photon fluence, not at all

a dose or dose equivalent.

2) " If I use a USRBIN with tracking of electron (part = electron) and a

AUXCORE card with a routine EWT74 is it the same as the dose Hp(10) for

electron (electron deep dose)?"

No. The personal dose is not implemented in FLUKA and -as clarified before-

has nothing to do with ETW74.

Moreover, "Electron deep dose" has no meaning in this context (I hope I'm

wrong, but I have the suspect that you want to use different quantities for

different contribution to the dose... this has no meaning!).

If you want to do the exercice to separate the electron and the photon

contributions (I would not do), use AMB74 or ETW74 and write a dedicated

USRBIN card for photons (using AUXSCORE) and another one for electrons.

3)" Eventually, if I want the total dose (photon + electron) do I have to use

the URSRBIN-Dose or a USRBIN with tracking ALL-PART with the card AUX-CORE and

the routine EWT74 (or maybe it is the same)?"

I think now it is clear: by using USRBIN with what(2)=DOSE or what(2)=DOSE-EQ

you get by default the total dose. In the dose equivalent case you get by

default the ambient dose equivalent H*(10), if you want EWT74 you have to

select it via AUXSCORE.

Hope this helps,

Regards,

Anna

Am Tue, 20 Aug 2013 15:00:21 +0200 schrieb Jonathan Le Gouestre

<Jonathan.LeGouestre_at_lemerpax.com>:

*> 2013 15:00:33 +0200 (CEST)
*

*> Sender: owner-fluka-discuss_at_mi.infn.it
*

*>
*

*> Dear Fluka experts,
*

*>
*

*> I have some questions on the use of USRBIN-Dose and USRBIN-Dose-eq. For my
*

*>problem I simulate a beam of electron in a tungsten target, and I want to
*

*>calculate the total dose and dissociate the contribution of electron and
*

*>bremsstrahlung photons.
*

*>
*

*> My questions are the next:
*

*>
*

*> 1. If I use USRBIN-DOSE-EQ is it the same as h*(10) (photon ambient dose
*

*>only)? Moreover, is it the same as USRBIN with tracking photon and a AUXCORE
*

*>card with a routine AMB74?
*

*>
*

*> 2. If I use a USRBIN with tracking of electron (part = electron) and a
*

*>AUXCORE card with a routine EWT74 is it the same as the dose Hp(10) for
*

*>electron (electron deep dose)?
*

*>
*

*> 3. Eventually, if I want the total dose (photon + electron) do I have to
*

*>use the URSRBIN-Dose or a USRBIN with tracking ALL-PART with the card
*

*>AUX-CORE and the routine EWT74 (or maybe it is the same)?
*

*>
*

*> Maybe there is another method to discriminate electron, photon and total
*

*>dose?
*

*>
*

*> Thank for your answer.
*

*>
*

*> Cheers,
*

*>
*

*> Jonathan.
*

*>
*

*>
*

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Dr. Anna Ferrari

Institute of Radiation Physics

Helmholtz-Zentrum Dresden-Rossendorf e.V.

Bautzner LandstraÃe 400

D - 01328 Dresden (Germany)

Tel. +49 351 260 2872

Received on Mon Sep 02 2013 - 09:18:03 CEST

Date: Mon, 02 Sep 2013 00:31:43 +0200

Dear Jonathan,

first of all, maybe it is useful to remember that the distinction between

photon and electron dose does not make sense in reality, because also in the

case of photons the dose is always entirely due to the secondary electrons

that they produce.

When with FLUKA you calculate the DOSE (the energy deposited per unit mass)

due to the photons, you see the effect of the transport threshold that

"forces" the photon below threshold to locally deposit his energy.

When on the other hand you calculate the DOSE-EQ (dose equivalent) due to the

photons, you fold the photon fluence with a set of conversion coefficients

that have been calculated on a proper phantom where, another time, the dose

was entirely due to the secondary electrons produced by photons.

The second thing that it is useful to clarify is that when you compute with

USRBIN a DOSE or a DOSE-EQ (in the second case by selecting the desired set of

conversion coefficient via the AUXSCORE card), you get by default all the

contributions coming from all the particles generated by your primary beam. If

you want to filter the contribution of a certain kind of particles you have to

declare it in the AUXSCORE card.

Coming to your questions, in 1) and 2) there is a bit of confusion between

ambient dose equivalent H*(10), personal dose equivalent Hp(10), effective

dose and sets of conversion coefficients from fluence to dose

equivalent/effective dose. I would suggest to look at this lecture (p. 14-16):

https://www.fluka.org/free_download/course/nea2013/Lectures/18_Activation.pdf

where you can find also a useful reference.

I would summarize that in FLUKA for your needs you can find:

- for ambient dose equivalent calculations: the conversion coefficients

fluence/H*(10), based on ICRP74 values (and values calculated by M.Pelliccioni

for neutrons above 20 MeV).

You explicitly select it via AUXSCORE with sdum=AMB74 (in any case this is the

default choice, you get it by selecting the DOSE-EQ scoring also without

giving the option AUXSCORE).

As said above, by default you get all the contributions to the H*(10).

- for effective dose calculations: conversion coefficients fluence/effective

dose.

They are implemented for three different irradiation geometries (please see

manual and lecture cited above).

The choice sdum=ETW74 selects the coefficients there are obtained by

considering, for each energy bin in each data set corresponding to a certain

kind of particle, the maximum coefficient of anterior posterior, posterior

anterior, right lateral and left lateral geometries.

This set of coefficients is therefore always conservative with respect to the

effective dose (which depends on the irradiation geometry). It is a very good

choice for shielding purposes.

...and now, let's start from the question 1:

1) " If I use USRBIN-DOSE-EQ is it the same as h*(10) (photon ambient dose

only)? Moreover, is it the same as USRBIN with tracking photon and a AUXCORE

card with a routine AMB74? "

No. If you use a USRBIN with what(2)=DOSE-EQ by default you get H*(10) with

all the contributions to the dose equivalent. If you want to isolate the

contribution coming from the photon fluence you have to filter it via

AUXSCORE.

Moreover: a USRBIN with what(2)= PHOTON select the photon fluence, not at all

a dose or dose equivalent.

2) " If I use a USRBIN with tracking of electron (part = electron) and a

AUXCORE card with a routine EWT74 is it the same as the dose Hp(10) for

electron (electron deep dose)?"

No. The personal dose is not implemented in FLUKA and -as clarified before-

has nothing to do with ETW74.

Moreover, "Electron deep dose" has no meaning in this context (I hope I'm

wrong, but I have the suspect that you want to use different quantities for

different contribution to the dose... this has no meaning!).

If you want to do the exercice to separate the electron and the photon

contributions (I would not do), use AMB74 or ETW74 and write a dedicated

USRBIN card for photons (using AUXSCORE) and another one for electrons.

3)" Eventually, if I want the total dose (photon + electron) do I have to use

the URSRBIN-Dose or a USRBIN with tracking ALL-PART with the card AUX-CORE and

the routine EWT74 (or maybe it is the same)?"

I think now it is clear: by using USRBIN with what(2)=DOSE or what(2)=DOSE-EQ

you get by default the total dose. In the dose equivalent case you get by

default the ambient dose equivalent H*(10), if you want EWT74 you have to

select it via AUXSCORE.

Hope this helps,

Regards,

Anna

Am Tue, 20 Aug 2013 15:00:21 +0200 schrieb Jonathan Le Gouestre

<Jonathan.LeGouestre_at_lemerpax.com>:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Dr. Anna Ferrari

Institute of Radiation Physics

Helmholtz-Zentrum Dresden-Rossendorf e.V.

Bautzner LandstraÃe 400

D - 01328 Dresden (Germany)

Tel. +49 351 260 2872

Received on Mon Sep 02 2013 - 09:18:03 CEST

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