Sentries at the Limits of Science

Safety in the CERN Particle Accelerator

27.01.2010 - A particle accelerator is used for fundamental scientific research at the European Organization for Nuclear Research (CERN) in Geneva. Nobody is allowed to be in the tunnel while e...

A particle accelerator is used for fundamental scientific research at the European Organization for Nuclear Research (CERN) in Geneva. Nobody is allowed to be in the tunnel while experiments are taking place - the radiation would be deadly. A key management system from Deister ensures that this cannot happen.

An atom was considered by the ancient Greeks to be 'unsliceable‘ - you couldn‘t get any smaller. Today‘s physicists don‘t find it so easy to stop at the smallest particle - there is apparently always something even smaller beyond that. And in the world of particles, for example, "small" means that just the core of the atom is comparatively as big as a pinhead lying on a football field (the case). At one tenth the size of this core you reach the protons, and if you reduce the size by a factor of one thousand you reach the quarks.

The security engineer by contrast normally works in an entirely different dimension, that of card forgers or heavyweight lock pickers. The tiny particles only become apparent to him when physicists, such as those at CERN, impose their will on these building blocks of our universe - when they chase them through the particle accelerator and make them dangerous to humans.

Standing Here Would Be Life-threatening

Around 7,000 highly-qualified scientists from 80 countries are investigating material here in this way. Strong electrical and magnetic fields abound in the kilometer-long circular accelerator about 100 meters underground. They ensure that the particles gain energy with each lap of the accelerator. The CERN physicists are currently building the most powerful accelerator of all time. This LHC (Large Hadron Collider) will be 27km long.
A lot of security equipment is also built in amongst the large amount of densely-packed equipment and instruments. The operators must be absolutely certain that no-one is in the accelerator tunnel as long as experiments are taking place.

First of all, a doubly-secured safety door with a fingerprint reader and video cameras already ensures at check-in that only authorized people can enter the complex. Security is heightened by a weighing system - in this way, only one person can enter at a time. The second door can only be opened by someone when the first door has been closed behind them. A Prox Safe Mini key management system from Deister Electronic is mounted at this second door and administers eight keys behind an automatic steel cover.

A Clear Overview: Safe and Well-arranged

Only an authorized person who takes a key from the system can get to the inner regions of the complex. In this way, the system knows exactly who is in the tunnel at any time. But even more importantly: before the particle accelerator can be activated, an automatic and compulsory check takes place to see if someone is still in the tunnel. A green light and the ability to activate the accelerator are only given when every one of the eight keys are inserted in the Prox Safe Mini.

The system doesn‘t just rely on electronics here. Because it‘s a matter of life or death, it was important for the CERN scientists that the system could cope with either a power failure or a computer failure. For this reason, there must also be a real physical connection between the key and the cylinder before clearance is given. The Prox Cylinder also ensures that no unauthorized person can use one of the keys. A special stick prevents anything else making the mechanical contact for as long as the correct key is not inserted in the lock.

Contactless And Wear-free

The doors are automatically opened and closed by the system. This avoids alarms that would otherwise be raised but often not heeded because of their frequency. A further advantage arises from the use of RFID technology: the Prox Cylinder and the Proxsafe tag on the key work together without contacts and therefore without wear and maintenance. The system is controlled from a web server. Any contactless reader from any manufacturer can be integrated into all existing systems.

Deister Electronic was the only company that could meet all the safety and technical requirements contained in the international tender, as Paul Gilardi of Deister reports. Also some purely practical advantages, such as the roll door construction of the housing that avoids bulky doors in narrow spaces, were welcomed by CERN. The use of Deister systems is already planned for other applications.


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