[Gate-users] Is photoneutron yield in Gate/Geant4 underestimated?

[von Vangerow Johannes]

Dear Nicolas,

many thanks for your suggestion. I included the ShieldingLEND physics list in GATE as you suggested. Using the new model, the neutron production rate is closer to what I expect from a simple calculation. Yet, it is still a factor 40-50% less than the calculated value. I’m not shure what is still causing this deviation. I’m using  the photoneutron crosssections from Dietrich  et al. (https://doi.org/10.1016/0092-640X(88)90033-2) for my calculations.

In Geant4, I get reasonable results using the Hadr03 example with a modified version GammaNuclearPhysics.cc including LEND processes as suggested here<https://geant4-forum.web.cern.ch/t/understimating-neutron-flux/999/10>. Do you know if there is a way to use this modified Version of GammaNuclearPhysics.cc in GATE?

Best regards

Johannes



Von: narbor <nicolas.arbor at iphc.cnrs.fr>
Gesendet: Sonntag, 16. Februar 2020 21:25
An: von Vangerow Johannes <Johannes.vonVangerow at ptw.de>
Betreff: Re: [Gate-users] Is photoneutron yield in Gate/Geant4 underestimated?

Dear Johannes,

From what I know (from Geant4 developers) you can now used ENDF/BVII.1 data for photonuclear reaction (as with MCNP) by selecting ShieldingLEND physics list in GATE.

As you said, previous version of Geant4 (< 10.04) used a parametrized model for photo-nuclear reactions that under-estimate neutrons production for many nuclei (with also a wrong threshold).

Results are clearly better now with the LEND model (ENDF data) for gamma energy lower than 20 MeV.

Best regards,

Nicolas

PS : as John said, the best is always to ask directly Geant4 User Forum for this kind of Geant4 physics questions.

***********************************************************************

Nicolas ARBOR

Maître de Conférences

Université de Strasbourg - Faculté de Physique et Ingénierie

Groupe de recherche DeSIs - Institut Pluridisciplinaire Hubert Curien

23, rue du Loess BP28 67037 Strasbourg Cedex 2

mail : nicolas.arbor at iphc.cnrs.fr<mailto:nicolas.arbor at iphc.cnrs.fr> / tel : 03.88.10.64.27

***********************************************************************
Le 03/02/2020 à 16:55, John Apostolakis a écrit :
Dear Johannes,

I suggest to post this and similar questions in the Geant4 User Forum (https://geant4-forum.web.cern.ch/ ) , instead of the GATE mailing list, for a response from more Geant4 users and developers.

John
===================================================
John Apostolakis,  EP Department, CERN



On 3 Feb 2020, at 16:13, von Vangerow Johannes <Johannes.vonVangerow at ptw.de<mailto:Johannes.vonVangerow at ptw.de>> wrote:

Hi,

I am just starting to perform simulations in Gate including Neutrons. Concerning that, I performed a simulation with 15MeV photons impinging on a thin (10µm) target. The simulation in Gate / Geant4 yields about a factor 3 less neutrons than a simple calculation using the respective crosssection. So far I tested W and Pb.

In a publication „Quantification of the validity of simulations based on Geant4 and FLUKA for photo-nuclear interactions in the high energy range“<https://www.epj-conferences.org/articles/epjconf/pdf/2017/22/epjconf_icrs2017_06023.pdf> it is stated that Geant4 underestimates the Neutron production. Is this really true? I am using the QGSP_BIC_HP physics list.

Best regards

Johannes





Dr. Johannes von Vangerow

Software Development


Phone: +49 761 49055-367

Fax:      +49 761 49055-70

Email:  Johannes.vonVangerow at ptw.de<mailto:Johannes.vonVangerow at ptw.de>

.

PTW-Freiburg Physikalisch-Technische Werkstätten Dr. Pychlau GmbH

Lörracher Str. 7 | 79115 Freiburg, Germany

www.ptw.de<http://www.ptw.de/> | Follow us: LinkedIn<https://de.linkedin.com/company/ptw-/>


.

Geschäftsführung: Dr. Christian Pychlau, Dr. Tobias Schüle

Registergericht Freiburg HRB Nr. 1673 | WEEE Reg.-Nr. DE 15599992


.

<ptw_logo.jpg>




<test_neutron_production.mac>_______________________________________________
Gate-users mailing list
Gate-users at lists.opengatecollaboration.org<mailto:Gate-users at lists.opengatecollaboration.org>
http://lists.opengatecollaboration.org/mailman/listinfo/gate-users




_______________________________________________

Gate-users mailing list

Gate-users at lists.opengatecollaboration.org<mailto:Gate-users at lists.opengatecollaboration.org>

http://lists.opengatecollaboration.org/mailman/listinfo/gate-users


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.opengatecollaboration.org/pipermail/gate-users/attachments/20200303/68b274ff/attachment-0001.html>