The Large Hadron Collider (LHC) of the CERN research center in Switzerland is "the biggest machine in the world", 140 meters below ground and with a cost of 3 billion Euros: In a 27 kilometer circular particle accelerator, protons or lead ions are smashed together almost at the speed of light. In the collision, a vast number of smaller particles are created, which are supposed to give insight into the innermost structure of matter - simulating the Big Bang.

For the renewal of the electronics in the particle accelerators, the VMEbus PC A20 is used. Computer systems with up to 20 of these VMEbus PCs are the central element for controlling and accelerating the particle beam in the LHC. Here, the beam is controlled and held on its path and the passing from station to station is monitored. The data has to be read by the sensors in real-time, while in the other direction, control commands have to be given to the equipment. The power converters, the radio frequency system for the acceleration, and the measuring systems around the beam are controlled. The placement of the synchronization points has to be calculated exactly because of the narrow timing in order to avoid loss of data.

The VMEbus single-board computer A20 is especially suited for harsh and safety-critical environments. Dependent on the processor type, it is specified for different temperature ranges and the system memory is soldered against shock and vibration. The CPU board supports a multitude of Intel® processors - starting from Core Duo or Core 2 Duo down to Single Core Celeron® M versions. Thanks to the TSI148 bridge controller, the SBC allows for a fast and reliable data transfer with 2eSST. The A20 is one of a small number of 6U computers offering space for 2 PMC or 2 XMC modules and numerous other connection possibilities. Additionally, four of the six PCI Express® lines which were originally intended for connection of XMC modules can be used to accelerate the data transfer.