[en] A new method for fabricating polystyrene ICF targets has been investigated. A solid solution of polystyrene (PS) containing a chemical blowing agent (CBA) is divided into small granules. These granules are blown into spherical shells in a vertical furnace. By varying the type and amount of CBA as well as furnace parameters, it is possible to produce PS shells 200-600 μm in diameter with wall thicknesses from 4-20 μm. (author)