Strange Flair Crash with LOW-PWXS

Dear FLUKA experts,

I’m using Flair in a Ubuntu setting within a container, but find that the program crashes when I add a LOW_PWXS to the input file. If such a card already exists on the input file, I am able to examine the geometry and navigate around in Flair, but the input tab simply freezes and I’m prevented from taking any further action.

Might anybody have some advice for how to deal with this? Perhaps Flair is searching directories within the container for the relevant cross section files and they are absent?

Thank you,


LOW-PWXS card needs a download of at least one additional package is required. You may not have downloaded this package. The download address is as follows: FLUKA libraries for low-energy neutron pointwise interaction cross sections | The official CERN FLUKA website

Yaoxuan, thank you.

I do have the ENDF files, but where is Flair expecting to find them?


Dear friends,

I’ve managed to solve this problem. As long as the data files are in the /usr/local/fluka directory, they seem to be found by Flair.

As an aside, what I’ve done is create a Docker image in order to use Flair exclusively to modify my input file and geometry— if it’s of interest to others, I would be glad to share it here. I did not want to perturb my local environment, and knew I’d be running FLUKA simulations from a Singularity container on a remote server; as it turns out, you can build such containers from within a Docker image too.

I’ve attached here the Dockerfile (747 Bytes), and a script (353 Bytes) I use to boot the image in order to forward graphics and conveniently share files with the directory from which the Docker image is booted.

Please note, I am not running FLUKA from within the container, merely editing input files.

All the best,