KINETICS OF PHYSICAL VAPOR TRANSPORT AT LOW-PRESSURE UNDER MICROGRAVITY CONDITIONS - I - DCMF FLIGHT HARDWARE AND EXPERIMENTAL CONDITIONS

An autonomously operating apparatus has been developed for the measure ment of the transport rate of mercuric iodide vapor. It was flown aboa rd the Space Shuttle STS-77 mission in May 1996. The results of the di ffusion coefficient measurement facility (DCMF) space experiment provi de a breakthrough in the understanding of the transport phenomena duri ng the physical vapor transport under low total pressures (0.5-3.5 mba r). The comparison of the transport data in microgravity and on earth could reliably be made only due to the sophisticated hardware developm ent. The design, construction and the technical performance of the app aratus are presented in Part I whereas the major results are discussed in Part II. (C) 1998 Elsevier Science B.V. All rights reserved.