Preparation of solid hydrogen targets for laser fusion research

A description is given of the construction of a cryostat for the preparation of solid H₂ and D₂ targets; the results of tests on the cryostat are also reported. Before the formation of a target, H₂/D₂ is supplied from outside along a special tube and is desublimated in a cylinder whose walls are cooled with gaseous helium evaporated from a helium bath. Solid H₂/D₂ is then extruded through a die of required shape into vacuum, forming a target which is illuminated with a laser beam through quartz windows. The cryostat construction is such that the shape of the target (cylinder, parallelepiped) can be varied and its dimensions (cylinder, parallelepiped) can be varied and its dimensions (diameter from 0.3 to 4.5 mm) altered. A target of this kind has a life of about 30 min.