A method for fabricating read-only copy protected optical medium comprising a light-sensitive material at positions capable of altering the data read during copying of the optical medium but permitting read of the underlying data in the reading of the optical medium. The elongate shaft assembly includes at least one primary shaft segment, and at least one secondary shaft segment removably coupled to the primary shaft segment, the secondary shaft segment includes a first gear. The condensable vapors are condensed by directly contacting a heat exchange liquid in the direct contact heat exchanger while the uncondensed light gases from the process stream form a separated light-gas stream.