Thanks your reply.
According to the suggestion： Dose rate calculations for isotropic cylindrical sources - Source Definition - FLUKA User Forum (cern.ch), I have modified my source_newgan_CYLI.f to perform isotropic sampling for CYLI-VOL, and it has been successfully built.
However, after plotting the projections of the source in the XYZ directions, the cylindrical source definition did not take effect, and it still shows as a point source. If it is a CYLI-VOL source, the projection at this time should be a straight line.
Could you please tell me what might be the issue?"
source_newgen_CYLI.f (21.8 KB)