A fiber extrusion system is described that produces frozen fibers of a
lmost any condensible gas. This extruder has the advantage of employin
g a closed-refrigeration system. To date, this system has produced fib
ers of H-2, D-2, and Ne of a diameter ranging from 100 to 130 mu m. Th
e extrusion occurs at a specific temperature which is several degrees
below the triple point of these gases. Once the fiber is extruded it c
an survive in vacuum for 20 min if the nozzle (extrusion) temperature
is lowered to 8 K. The length of these fibers can be of the order of 1
m. D-2 fibers will be used in a staged Z-pinch experiment as a fuel f
or thermonuclear fusion. For this application a guiding structure is n
eeded to position the fiber between the electrodes with millimeter pre
cision, without significantly affecting its quality. (C) 1996 American
Institute of Physics.