Proceedings of the 1991 Cryogenic Engineering Conference held in Huntsville, Alabama, June 11-14, 1991.

The 1989 Cryogenic Engineering Conference, meeting jointly with the International Cryogenic Materials Conference, was held on the campus of the University of California, Los Angeles from July 24 to 28. Professor T.H.K. Frederking was the conference chairman. The Conference had previously met at U.C.L.A. in 1962 and 1969. A special symposium, "A Half Century of Superfluid Helium," was a significant part of the program of CEC-89. We were especially fortunate to have Professor Jack Allen of the University of St. Andrews, Scotland present at the Conference; his paper, "Early Superfluidity in Cambridge, 1936 to 1939," was a delightful, often humorous account of the early experimental work with superfluid helium. Professors V.L. Ginzburg and J.L. Olesen could not be present for the Symposium, but provided papers which are published in these proceedings. The late Bill Fairbank, responding graciously to a last-minute invitation from Professor Frederking, presented a wonderful account of superfluid research in the United States in the post-war years.

The Sixth International Cryogenic Materials Conference (ICMC) was held on the campus of Massachusetts Institute of Technology in Cambridge in col laboration with the Cryogenic Engineering Conference (CEC) on August 12-16, 1985. The complementary program and the interdependence of these two dis ciplines foster the conference. Its manifest purpose is sharing the latest advances in low temperature materials science and technology. Equally im portant, areas of needed research are identified, prioriti-es for new research are set, and an increased appreciation of interdisciplinary, interlaboratory, and international cooperation ensues. The success of the conference is the result of the. able leadership and hard work of many people: S. Foner of M.I.T. coordinated ICMC efforts as its Conference Chairman. A. I. Braginski of Westinghouse R&D Center planned the program with the assistance of Cochairmen E. N. C. Dalder of Lawrence Livermore National Laboratory, T. P. Orlando of M.I.T., D. O. Welch of Brookhaven National Laboratory, and numerous other committee members. A. M. Dawson of M.I.T., Chairman of Local Arrangements, and G. M. Fitzgerald, Chairman of Special Events, skillfully managed the joint conference. The contributions of the CEC Board, and particularly its conference chairman, J. L. Smith, Jr. of M.I.T., to the organization of the joint conference are also gratefully acknm.ledged.

The Fourth International Cryogenic Materials Conference (ICMC) was held in San Diego, California in conjunction with the Cryogenic Engineer ing Conference (CEC) on August 10-l4, 1981. The synergism produced by conducting the two conferences together remains very strong. In the ap pl1cation of cryogenic technology, materials continue to be a demanding challenge, and sometimes, an obstacle. The association of materials and cryogenic engineers increases their awareness of recent research in each other's fields and influences the course of future research. Many contributed to the success of the 1981 conference. J. W. Morris of the University of California--Berkeley was ICMC Conference Chairman. E. N. C. Dalder of Lawrence Livermore Laboratories was ICMC Structural Program Chairman; D. C. Larbalestier of the University of Wisconsin- Madison, and D. K. Finnemore of Iowa State University were Superconducting Materials Program Chairmen. Local arrangments were expertly coordinated by R. E. Tatro of General Dynamics--San Diego. The CEC Board, especia11y their conference chairman, T. M. Flynn, of the National Bureau of Stan dards, Boulder, contributed very substantia1ly to conference planning and implementation. All of their efforts provided the foundation of the largest CEC/ICMC ever. We thank the Office of Naval Research and the Office of Fusion Energy and Basic Energy Sciences of the Department of Energy for providing needed financial support for the conference. Fina11y, we especially thank M. Stieg, who prepared the papers for the new procedures and format used in this volume."

Part A: Heat and Mass Transfer in Helium II: A Brief History of Cryogenics; R.G. Scurlock. Applications of Helium II: A Liquid/Gas Phase Separator for HeI and HeII; P.J. Shirron, et al. Heat Transfer in Cryogenc Fluids; Heat Exchangers; Thermoacoustic Oscillations. Insulation. Applications of Superconductivity: Magnet Stability; Coil Protection. Applications of Superconductivity: Magnets and Other Devices. Applications of Superconductivity: Cryogenic Techniques. Refrigeration for Electronics. Refrigeration of Superconducting Systems. Part B: Compressors, Expanders, Pumps for Liquid Helium. Magnetic Refrigerators. Pulse Tube Refrigerators. Cryocoolers. Properties of Cryogenic Fluids. Cryogenic Applications: Transportation. Cryogenic Applications: Space Science and Technology. Cryogenic Applications: Equipment for Space. Cryogenic Instrumentation. Miscellaneous Cryogenic Techniques and Applications. 170 additional articles. Index.