COMPASS Visits: Itinerary

2022 was the last COMPASS data taking year, the experiment is now in data analysis phase.
The COMPASS apparatus has been transferred to the AMBER (NA66) experiment. Visit the following page for more information https://amber.web.cern.ch


The STANDARD ITINERARY enters the experimental hall EHN2 (building 888) from the Jura side (back of the building) and proceeds through door PXX 211.1 to the beamline. A large poster of CERN's accelerator complex can be used to explain where COMPASS is located and that it is a fixed target experiment at the end of a beamline. The tunnel can be entered until the stop sign on the floor/red-white cable. After the tunnel, the itinerary follows the beamline downstream , such that the visitors can look through the hole in the wall towards the experiment. The itinerary leaves the beamline area through door PPX 211.2 and then EHN2 through the same door used when entering the building.

After a short walk on the road EHN2 is entered again through PPX 221.1 and the visit proceeds via the inside staircase to the gallery on the Jura side of 888. At most two groups (24 persons + 2 guides) may be present on the gallery simultaneously. The visit is finished at the downstream end of the gallery. The building can be left via the outside staircase, however, the guide must make sure that it is not too slippery (rain, snow, ...) before the visit starts. If the outside staircase cannot be used, after finishing the visit, the guide needs to take the visitors back upstream on the gallery and leave EHN2 again through PPX 221.1.

The STANDARD ITINERARY, as described above has been officially accepted by CERN's safety inspection: EDMS document. The graphical representation of the STANDARD ITINERARY described above looks as follows:

In case potentially dangerous work is performed in and around the target area (early 2015), it is strictly forbidden to take groups along the STANDARD ITINERARY. Instead, an ALTERNATIVE ITINERARY can be used. Since the inside stairs passes along the target area, the only way to reach the gallery safely is via the outside staircase. The exit door at the downstream end of the gallery can however not be opened from the outside. To be able to enter the building via this door, when the ALTERNATIVE ITINERARY is used, the COMPASS Visits Coordinator will place a stopper before every visit and remove the stopper after each visit, such that the door does not fall in the lock. The graphical representation of the ALTERNATIVE ITINERARY described above looks as follows:

The shortest emergency routes leaving the building are indicated below. If the building is left on the Jura side (top of picture), the evacuees have to walk around the building to the collecting point.

Finally, the location of safety equipment (only along the itinerary) is shown. In case of fire, never try to put it out yourself, intoxicating gases can be present and the fire can spread fast and unexpectedly. Always inform the CERN firebrigade directly: 74444! General alarm switches can be used as well to inform about a calamity, it will trigger an alarm for the CERN fire brigade. In case of small injuries, medical kits are present in the control room and workshop. In this case, please ask the local personnel for help, since all doors are typically locked by key.