A concept for earthquake protection of the Bucharest tandem accelerator

A concept for an earthquake protection of a tandem accelerator has been developed starting from a better understanding of the earthquake effects upon an FN column structure as a result of dynamic interaction between the ground, building and accelerator. The characteristics of earthquakes in Bucharest as well as the preliminary full-scale vibration tests are described. The main requirements for an efficient earthquake protection system are derived. These requirements are best met by a protection system that performs the vibration isolation of the accelerator tank by supporting it on spring and damper units. By means of specially designed devices (''mechanical fuses''), these units are blocked under normal operation conditions to ensure the alignment of the accelerator and are released in case of an earthquake whose acceleration exceeds a certain limit. Such a vibration isolation system might be useful for other scientific or industrial equipment too. (orig.)