An ampoule is designed for inclusion within a multi-zone furnace which forms particularly well in space. The ampoule includes an outer quartz wall which has outward projections supported by complementary members of a space furnace and minimizes the transferral of vibrational forces through the ampoule. An inner quartz containment member includes a hollow projection for holding a semiconductor seed, the containment member extending toward a charge containment section. A tube is positioned between an outward end of the charge and the interior wall of the ampoule for maintaining the charge in place during space travel. Further, the tube serves as a vapor chamber for accommodating overpressurization of a vapor component such as arsenide, in the case a gallium arsenide crystal is being grown. The ability to accommodate overpressurization of the vapor allows a uniform and homogeneous single crystal to be grown.