Picosecond timing system and related metrology. Application to the Megajoule laser

This thesis document introduces the study and the design of a timing system innovating in its performances and its low cost. The principle and the concept apply to big instruments of physics such as the Laser MegaJoule (LMJ). The goal of our system is to synchronize the laser pulses on the target in a temporal window of 60 ps (60 10^-12 s). It must ensure the coherence of the triggering of laser pulses and measurement systems. The number of synchronization signals for the LMJ is higher than 8000. They are delivered over an area of about 10000 m² with a relative accuracy which can reach 15 ps RMS between outputs (60 ps peak to peak), in single shot or recurrent mode. The GPS system, which is by comparison one of the best synchronization systems, has a relative accuracy of a few ns. The feasibility studies lead to a digital link using standard components of telecommunication at 155.52 Mb/s, with an option to compensate the temperature drift of the fiber optic and to design of numerical counters using the programmable component has allowed the principle and the concept of the timing system. The solution is based on a high rate optical digital link, with low jitter, ensuring the transport of trigger signals and of a temporal reference in ail useful areas of the building. A delay generator with subnanosecond performances has been developed for the prototype architecture of the timing system. The performances of the timing system are the following: the jitter is less than 25 ps RMS, the resolution is better than 10 ps and the programmable delay dynamic reaches more than 1 s with an accuracy of 100 ps. (author)