[Gate-users] electron positron annihilation in 3 photons

[John Apostolakis]

Dear Meysar, ( David, )

I am reliably informed that the upcoming release of Geant4, version 10.5, includes a process for three-photon annihilation of positrons.  Full validation of this is pending.

Also it is not included in the pre-constructed physics lists, so it must be configured by the user.  I think that in terms of GATE this would mean that some C++ coding would be required to use it.

I note that Geant4 version 10.5 is scheduled for release this Friday, December 7th.

Best regards,
John
===================================================
John Apostolakis,  EP Department, CERN
SFT (SoFTware for Experiments) Group
Office: Building 32/ room R-003 (ground floor),  Mail: J27210
Email:  john.apostolakis at cern.ch<mailto:john.apostolakis at cern.ch>       Office Tel:  +41-22-767-7239
------------------------------------------------------------------------------------------

On 5 Dec 2018, at 14:13, David Boersma <david.boersma at acmit.at<mailto:david.boersma at acmit.at>> wrote:

Hi Meysam,

(Sorry, you get this twice, because I erroneously sent this to you personally instead of to the list.)

I'm afraid you are out of luck. Check the physics reference manual of Geant4:
http://geant4-userdoc.web.cern.ch/geant4-userdoc/UsersGuides/PhysicsReferenceManual/html/electromagnetic/electron_incident/annil.html

"The process G4eplusAnnihilation simulates the in-flight annihilation of a positron with an atomic electron. As is usually done in shower programs [NHR85], it is assumed here that the atomic electron is initially free and at rest. Also, annihilation processes producing one, or three or more, photons are ignored because these processes are negligible compared to the annihilation into two photons [NHR85][MC70]."

Looks like you will need a different simulation platform, something that is not relying on Geant4. Sorry!

HTH,
David
________________________________________
Von: Gate-users <gate-users-bounces at lists.opengatecollaboration.org> im Auftrag von Meysam Dadgar <meysamdadgar10 at gmail.com>
Gesendet: Mittwoch, 5. Dezember 2018 11:32:30
An: gate-users at lists.opengatecollaboration.org
Betreff: [Gate-users] electron positron annihilation in 3 photons

hello dear Gate users
I have a question about electron positron annihilation, in physics process it seems that the annihilation of electron and positron in 3 or more photons disregard, is there any model to consider these photons also, because these photons are very important for me.
Best regards
Meysam
PhD student of Biophysics
Poland
_______________________________________________
Gate-users mailing list
Gate-users at lists.opengatecollaboration.org
http://lists.opengatecollaboration.org/mailman/listinfo/gate-users
_______________________________________________
Gate-users mailing list
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/20181205/a5656156/attachment.html>