CERN — The European Laboratory for Particle Physics

Access to the LHCb cavern

1) Get the necessary safety training

In addition to the general mandatory courses you need to follow the courses below to be able to access the UX85 cavern:

These courses are web-based and available at
If your training and access ranks are still valid (check via you do not need to take the above courses until the expiration of your access rights approaches.

If you need to access the VELO alcove, the area close to the beam pipe between open calorimeters or the adjacent LHC Tunnel, you will have to take an additional half-day classroom course Radiation Safety - Controlled area – Initial.
If you already had this training rank, but took the course more than 3 years ago, you only have to enrol for the online Radiation Safety – Controlled Area – Refresher.

When redoing courses for the renewal of your access rights, it is possible that additional online courses may be required by the new learning platform. These will be indicated to you by the platform when you try to enrol to the course. If you encounter any problems while trying to take these courses, please open a ticket at the CERN Service Portal by clicking on the “Contact: Safety Training” link on the course page.

If you need to work at a height of 8 m or more above the cavern floor (e. g. on the calorimeter gantry) you need to follow the classroom-based course Self-Rescue Mask.

2) Submit an access request for "LHCb_U (UX85: LHCb underground)"

via "Request access" on the left-hand menu of

At the same time, request an access authorization for LHCb_S (LHCb surface buildings).

If it is your first request, send a copy for information to your project leader and mention your project (VELO, Muon, etc.) in the comments.

3) Obtain a dosimeter

Go to Building 55 to get an individual dosimeter and activate your biometry.

4) Submit an IMPACT request

Explain who intends to do what, how and when.

Access will be granted only once the IMPACT is approved and for the duration of the task.

Access to Point 8 surface buildings and the control room

Submit an access request for LHCb_S (LHCb Surface Buildings), providing a meaningful justification (e. g. "LHCb Shifts" or "LHCb piquet").

Access to the SXL8 assembly hall

Submit an access request for 3852-R-001 (LHCb_Facilities 3852), providing a meaningful justification.

Access as escort for visits

Accessing LHCb/Delphi underground areas as escort for visits

     Pit 8