TOPAS dose engine for photon dose calculation

[joshishalu]

Hello,

First of all, thank you for all your hard work with matRad! I have been using it in photon mode
to generate some simple plans with the SVDPB dose engine. I want to move to monte carlo dose engine
and have generated phasespace files in TOPAS for this purpose.
But I am running into some problems while using the phasespace files. The GUI displays a thin film
like dose map after running the dose calculation. I have been trying to understand this behaviour
but I am currently out of ideas . Any help will be greatly appreciated.
Thanks!

[wahln]

Okay, from the picture it is difficult to assess what could be going wrong.
Maybe a script on how you run the simulation and the created TOPAS parameter file would help.

Some additional questions:

• Does it work when you replace the phase space source in your TOPAS parameter file with a simple "Beam" source with, e.g., 6 MV photons?
• What kind of machine are you modeling? An MV LINAC? a kV source? To me, this could also look like only electrons entering the air or the source being positioned at a weird spot

[joshishalu]

basecode.txt
beamsetup_parameter.txt
phasespace_header.txt
Thank you for your quick response!
I have added a part of my script, the TOPAS parameter file and header for the generated phase space file. To answer your questions:

1. Yes, when I use the uniform beam setup, the dose looks fine, it works.
2. I am modelling a 6 MV FFF LINAC.