Presentation of fast high voltage switches

In the framework of the SILVA (isotopic separation by laser) project, the French CEA has developed an innovative technology concerning fast high voltage and high current switches. This technology involves semi-conductors and proposes modular sets made up of 350 MOSFET transistors able to switch 5500 V, 1000 A in 20 nanoseconds. The reliability level is high: the average life-time being over 20000 hours. This reliability is based on the redundancy brought by the series connection of the components. In a set of N series-connected components, if the number of components is greater than the just necessary number required to hold the voltage, the failure of one component does not spread to others. The device goes on acting and it appears that a certain number of failed components can be tolerated. (A.C.)