CERN — The European Laboratory for Particle Physics

01 Feb 2019

GPS Coordinates : 46°14'29"N 6°5'49"E
Chemin Bois-Candide, F-01210 Ferney-Voltaire


Heavy handling operations are currently underway in the UX85 and therefore no visits of the LHCb underground facilities / DELPHI are allowed. 

Depending on the progress of the work and ongoing discussions with the Safety Department, we will reconsider the situation in the coming weeks. Visits could resume, but only on weekends.

The surface exhibition will remain open to visitors. LHCb members should contact the LHCb Secretariat if large group (> 15 people).
LHCb_S access is requested.

Other potential visitors who are not LHCb members should contact the CERN in order to visit other facilities.

Visits to the LHCb facilities can be organized by the LHCb collaborators.

If you are planning a visit to the pit, the first step is to send an email to, precising date, time, total number of participants (visitors + guides). We will then be able to inform you if your visit can take place or not.
Due to the high number of requests, it is recommended to plan visits well in advance.

If the visitors are coming by bus, it should let the visitors down at the gate. Visitors will be welcomed here. A parking for the buses is available outside the site and it can wait there for the visitors to pick them up at the end. Visitors will be direct there at the end of the visits. (see picture for access)

For safety reasons, the following rules apply to all visits at Pit 8 without exception.

Visitors must be able to climb stairways. Persons equipped with any of the following: pacemaker, defibrillator, electronic medicine dispenser, hearing aid, metal implant, are not authorised into the undeground area, unless the dipole magnet remains off during the visit.
It is not allowed to climb metallic structures and to enter barracks.

A visit to the underground area (Delphi and/or LHCb) of Pit 8 would be allowed providing that:

  1. It is given by an LHCb guide who
    1a) has the required access authorisations (see Access to Experimental Site on the LHCb homepage)
    1b) has been appointed as guide. See details on how to become an LHCb guide.(List of LHCb guides).

  2. An Impact form for the visit has been submitted and approved (see how to do so in guidelines)

  3. The number of visitors per guide does not exceed 10. Additional restriction applies if minor are present
    (See here for details)

  4. At the beginning of the visit the guide reminds the visitors of the safety measures (you can find them and print them from here)

  5. The LHCb guide during the visit must be equipped as follows:
    - wear an helmet
    - wear a working head light or carry a working flash light
    - wear safety shoes (Shoes and flash lights are available at the control room, if needed)
    - carry a mobile phone. (The phone number must be entered in the Impact form)
    - carry own personal dosimeter. (It is recommended to read the dosimeter before going underground)

  6. Tokens, biometry keys can be retrieved shortly before the visit from the key cabinet in the control room.
    The cabinet can be opened with the guide CERN card

  7. At the end of the visit, the tokens and biometry keys should be returned in the same slot of the key cabinet by the guide

  8. At the end of the visit the supervisor has to fill the report information in the visit report (see "After the visit" in the guidelines)

  9. The visit can be cancelled on short notice for operational or safety reason


Each visitor must :

  1. wear a safety helmet (available in SX85)

  2. be equipped with closed shoes (no high heels, sandals, etc.)

  3. stay with the group and must not wander around by himself (herself)


For more information do not hesitate to contact the LHCb Secretariat 

(78591 or by email) / Official Press Brochures (E / F / G / I)