Modulator wheel in proton radiotherapy

Dear Fluka users,

I am trying to simulate a modulator wheel in a simple problem with a pencil proton beam impinging on a water cylinder target. I used the loop function over the angle defined through the card #define creating six simulations where just the angle changes (0, 60, 120, 180, 240 and 360 degrees). I also add the rule +\I-\d\d\d\d_fort.\U to each of the six simulations, but when I plot the results I obtain the same as for a single beam without the loop function and without the wheel. Should I see wider Bragg peak, extended over a larger area? Maybe the beamposition is inappriorate. Which region should I set the beamposition or other reasons? I attach the input filesProton_beam.inp (3.0 KB) . Thank you again for the help!

Best Regards,


Could you post also your .flair file. It seems to me that your rotation wheel is not properly modified with the angle variable. Or maybe there is something wrong in the processing of the results

Look the images below for 0,60,…240deg Your beam is at [-0.5,-0.5,-2.5]

0 60 120 180 240 300

Dear vasilis,
I have posted my .flair fileProton_beam.flair (5.2 KB) . Thanks for your help!

Best regard,

This thread was obsoleted by the new flair version