New concepts for access devices in the SPS personnel protection system

The accelerator facilities at CERN span large areas and the personnel protection systems consist of hundreds of interlocked doors delimiting the accelerator zones. Entrance into the interlocked zones from the outside is allowed only via a small number of access points. These are no longer made of doors which have left their place to turnstiles and then to mantraps or Personnel Access Devices (PAD). Originally meant for high security zones, the commercially available PADs have a number of CERN-specific additions. This paper presents in detail the purpose and characteristics of each piece of equipment constituting the access devices and its integration within the personnel protection system. Key concepts related to personnel safety (e.g. interlocked safety tokens, patrols) and to access control (e.g. access authorisation, biometric identity verification, equipment checks) are introduced and solutions discussed. Three generations of access devices are presented, starting from the LHC model put in service in 2008, continuing with the PS devices operational since 2014 and finally introducing the latest model under development for the refurbishment of the SPS Personnel Protection System.