How to define a gas source?

Dear fluka experts
Suppose I now have a bottle filled with CO2 gas, and CO2 has 14C with 10% abundance, first the electrons will lose energy in the gas, and then the electrons will pass through the tank, and I want to get the electron energy spectrum measured outside the bottle.
How to define the source? I didn’t find a topic about gas sources in the forum.

It seems to me, that you want to define a volumetric source.
Have a look at this thread: Isotopes in radioactive clouds

yes, but this link you gave me doesn’t have the details of the simulation. Can you give me a little more detailed steps?

For the volumetric source, have a look at the lecture on source from the last Fluka course.
For the definition of a gas, have a look at the material lecture (COMPOUND card and density value).

Hi amario thanks for your reply. I am sorry that my previous description was not thorough enough,I didn’t build a model, but what I am trying to create is a more complex volume source composed of multiple bodies(yellow in the picture), I find a similar topic like this:Volumetric source of complex geometry - #2 by horvathd. They use the source.f but I have no fortran programming experience. I used the source_newgen.f, and I know source_newgen.f is a new version of source.f. So can you give me the source_newgen.f?

source_newgen.f is distributed with the code, you already have it in your installation