Save secondary particle information of neutrino incidence

Dear Fluka experts,
I want to get the secondary particle information which generated by neutrino for each event. So I used the USDRAW entry to save the secondary particle information(3d momentum, Energy, generating point) and modified the mgdraw.f file. But I have the following question.
1.In my mgdraw.f file, I opened a txt file called “Neutrino” , but there is no any txt output file was created after run.
2.I just found that the parameters of the vertex coordinates are called XSCO,YSCO,ZSCO from manual, but I don’t know the names of the parameters of energy and 3d-momentum of the secondary particles. Where can I find the names of these parameters?

There are my input file and mgdraw.f
mgdraw.f (10.0 KB)
neutrino.inp (1.1 KB)


Hello @sdw21,

You need to explicitly un-discard the neutrino transport (since it is by default switched off) for your input to generate results. Check in the manual the use of the DISCARD card, setting any of the WHATs to “-NEUTRIE”.

To properly get the information using USDRAW of the secondary particles I advice you to take a look at this and this post. The energy and momentum are obtained through ETRACK and PTRACK, respectively, as also detailed here. I think in your mgdraw.f routine you would also need to specify the output format properly to not raise an error, at first instance i.e. by using WRITE (IODRAW, *) … .

Taking a quick look at your input it seems that the TARGET region is not well defined and you probably also don’t need two USERDUMP cards.

Cheers, hope this is helpful. Don’t hesistate to ask further questions!


Hello Andreas,
Sorry for replying so late. Thank you very much for your suggestions, I have read the talk you send to me. Now I change my input file and mgdraw.f, and the information which I need has been saved in a data file. But I still have some problem as following:

  1. I shoot 2GeV electron neutrinos into the water medium, but there are some electron neutrinos with primary information are recorded in the data file, does this mean that the source particles are also being recorded? And I shoot 100 neutrinos, but there are only 50 neutrinos with primary information are recorded, does that mean that only half the neutrinos reacted?

  2. It seems that all the secondary particles are recorded in the data file, but how do I know which particles are from the same neutrino, and are there any variables that can be used to determine that?

  3. It seems that every interaction is recorded, such as neutrinos scattering to produce electrons, which in turn cause electromagnetic showers. So how should I record only the particles directly produced by neutrinos, are there any physical quantities that can be used to make this selection?

There are my input file, mgdraw.f and output file
mgdraw.f (10.6 KB)
neutrino.inp (1.3 KB)
neutrino001_output.dat (67.3 KB)