Simulation not generating anything

Dear@ceruttif ,
It works.
After I run the file,it does not generate anything.I think there maybe something wrong with BEAMPOS.I want to define a point source directly above the fiber, which is perpendicular to the fiber,if it have something wrong?

Can you please share your updated flair file?

Here is my file.Look forward to your help.
target.flair (3.2 KB)

Dear @xiongbp,

As soon as I open the geometry tab, I can see that there is the “Errors found” message, which means that you have errors in your geometry. Fluka cannot work if there are errors in geometry.
Please, have a look at the lectures about geometry and geometry editor and then fix the errors. You should at least try to debug your input before asking for help.