From what I see in your input, the limits for USRBIN exceed your geometry too much.
I added two USRBINs - one for electrons and one for photons (from what I understand, you are interested in scoring X-rays).
sphere_modif_k.flair (3.0 KB)
yes i’m interested in scoring X-rays thank you so much i will check it
Just to clarify: there is no “spherical” USRBIN in Fluka, what you are using is a cylindrical USRBIN.
Dear @amario can you please explain more
Available 3D meshes are Cartesian, as a function of x/y/z, and cylindrical, as a function of r/phi/z, where r is the radius (i.e. distance from the cylindrical mesh axis) and phi is the azimuthal angle.
There is no spherical mesh, as a function of r/theta/phi, where r is the distance from the spherical mesh centre and theta is the polar angle.
Dear @ceruttif thank so much for this clarification
Maybe this post is of any help?
@danipuerta thank you for help