First Results on the Prototype of the Laser-Megajoule Cryotarget Positioner

The Laser Megajoule cryotarget positioner will be used to set the cryogenic targets at the center of the experimental vacuum chamber. It will consist of a 6-meter carbon boom at the end of which a target will be held by a cryogenic grip at 20 K. In the French concept, the targets will be transferred at 20 K to the cryotarget positioner using another cryostat. Some of the specifications are very ambitious. Indeed, the targets must be positioned with a high accuracy (+/-5 μm), the temperature must be controlled with a very good stability and the cryostat must have a 5 day autonomy. To reach these requirements, some technical solutions have been considered. To validate these choices, a scale one prototype has been studied and built at the Low Temperature Laboratory (SBT) of CEA/Grenoble (France). We present here the first results obtained with this prototype.