Since 1983, the "Science and Defense" prize has been awarded each year to the most outstanding and valuable scientific contributions to national defense. It is organized by the DGA's Mission for Scientific Research and Innovation (MRIS).
Mastering a thousandth of a degree Celsius in the "megajoule laser
Jean-Paul Périn, director of research at the CEA in Grenoble, is working on the cold chain required for experimental simulations on the "megajoule laser" (LMJ). In the LMJ, several dozen laser beams focused on a target are capable of reproducing extreme pressure and temperature conditions in the laboratory, comparable to those found in stars or in a thermonuclear device. This target, a ball of 2 millimeters in diameter, must be kept in extreme cold conditions until the moment of the laser "bombardment". Close to absolute zero (about -255°C), the temperatures at which these cryogenic targets are cooled must be stabilized to within a thousandth of a degree.
For this, Jean-Paul Périn has developed cryogenic systems that ensure the transfer of the target during the different manipulations (transport, storage, positioning in the LMJ chamber) while guaranteeing the cold chain. The system will enter its industrial phase in early 2009.