Low-energy neutron reaction filtering

Dear experts,
I am currently simulating neutron bombardment on iron and need to collect event information where the neutron energy deposition in iron exceeds 10 keV.
I have implemented the ENDRAW routine in MGDRAW, but file 99 shows no output.
When I filter only for neutron, all regions recorded in file 90 show as “1” (black hole).

I don’t know what my mistake was. I would appreciate it if anyone can help.
Fe-n.flair (2.0 KB)
mgdraw_n.f (4.2 KB)
Fe-n001_fort99.txt (57 Bytes)
Fe-n001_fort90.txt (4.3 MB)

Hello Yuan,

thank you for your question, I will take a look at your files and let you know soon.

Thank you

Stefano

Hello Yuan,

sorry for the delay, I thought there was something wrong with the way you write the file (no need to open units, and also there was a weird closing of the output unit in a separate entry of MGDRAW). Regardless, this is not the issue.

The main issue is that ENDRAW scores energy losses to a material, but neutrons do not interact electromagnetically, and the interactions they undergo result in nuclear recoils or other secondaries. These particles are then transported, and thus are not counted as losses, just energy transfer. A user had a similar question last year in this post. The ENDRAW is then invoked as charged secondaries slow down in the material, depositing energy in a form that is not transported (below delta-ray production, e.g.)

I hope this clarifies the issue,

Stefano

Thank you very much for your help.
Additionally, Can I ask one more question? If I want to score the transfer of neutron, what method should I use?