IMPORTANT: Registration and package download FAQ

Here are Frequently Asked Questions about the registration process and FLUKA packages download. Due to data privacy considerations, no request concerning those topics will be handled through the forum. Instead, if you still face an issue even after reading questions and answers below please use the contact form to get in touch with us. Thanks!

I filled in the “FLUKA User Registration” webform but I can still not download the FLUKA packages?

Attention: many users think they have registered after they have completed step 1 of the registration process (creation of a CERN lightweight account). This is not enough, you have to complete step 2 as well.

I am certain that I completed both steps of the registration process, however I still can’t download the FLUKA packages. What should I do?

Registration as a FLUKA user is subject to approval. Once you subscribed to the e-group, please account for up to two working days until your subscription request has been processed. You will receive an automatic confirmation email upon approval. Please note that, once you have received the confirmation, it might still take a couple of hours until the registration database has been updated and you can download the FLUKA packages.

I registered on the FLUKA website and received confirmation, however I encounter the following error : “401 - Unauthorized” - when trying to download the packages

There can be two reasons why you face this error.
First it can be because you are logged in to a different CERN (lightweight) account than the one with which you registered. Please make sure that you are logged in with the right account when trying to download files.

The second is that you might be trying to download source code packages when you are only entitled to access binary ones. Every registered user should have access to the binary packages. If you think that you should have access to the source code but the download fails, reach out to us through the contact form.

Can I use FLUKA as a private individual for academic or educational purposes?

Yes, you can get access to the FLUKA Software with binary libraries. But you have to specify during the registration procedure (Step 2) for which purpose you intend to use FLUKA.

Does registration automatically give me the right to download the FLUKA source code?

The source code can only be downloaded by registered users affiliated with an academic institute/university which obtained an institutional license from CERN (see licenses ). Any institute/university which is interested in obtaining such a license is encouraged to use the contact form. The source is also available to CERN Staff members and Fellows who registered on the website.

We would like to have a central installation of FLUKA on a computing cluster at an university/institute. Do we need to obtain an Institutional FLUKA licence?

No, an institutional licence is not needed if the installation is based on the FLUKA binary libraries. However, it is mandatory that all users of the central FLUKA installation register on this website (“I am affiliated with an institute … NOT holding an institutional FLUKA licence”) and accept the FLUKA Single User Licence Agreement.

Do I need to register for downloading the graphical user interface Flair on

No registration is needed for downloading Flair.

I subscribed as a FLUKA user on, but I would to unsubscribe. How can I do that?

Please fill in the contact form, chosing the option “Unsubscribe as a FLUKA user”. Make sure that use the same email address as in the registration process. Your registration data will then be deleted and you will no longer be able to download the FLUKA packages on this website.

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