The sphere radius in the "BEAMPOS"

Source Definition
1

Dear experts,
I want to know under what circumstances should I choose FLOOD in the BEAMPOS ?
And what is the meaning of the “WHAT(1):sphere radius” when the “SDUM=FLOOD”?
How can I establish the Location and direction of the source when choosing FLOOD ?

2

Dear Junjie,

you can use BEAMPOS with FLOOD, if you want to use a spherical surface source, where the fluence inside the sphere is uniform and isotropic.

In this case the radius means the radius of the sphere, where the primaries are started.

See slide 26 of this lecture:

To specify the position of this sphere, you need to use a second BEAMPOS card with Type: POSITIVE [SDUM = blank]. If there is no second BEAMPOS card, the the sphere will be located at the origin of the coordinate system.

The direction specified on the second BEAMPOS card, and the angular divergences on the BEAM card are disregarded, since they are automatically set to produced the uniform and isotropic field inside the sphere.

Cheers,
David

1 Like
3

Thank you very much for your answer.
I am a beginner of FLUKA, When I encounter some problems, I will look for answers in the manual, but there are some problems that can not be solved clearly in the manual. In the pdf file I can clearly see the definition of each option in the software, and can solve my confusion quickly.
Could you please tell me where can get these pdf file? Or if you can share them to me, I would be very grateful.

4

Dear Junjie,

If I understood your question correctly, you are looking for lectures on other topics as well.

You can find the material of the latest online training here:

The pdfs are in the Timetable. Look for the paperclip icon, next to the lecture’s title.

Cheers,
David

1 Like
5

This is just what I want. Thank you very much for your kind sharing.