Once again the annual Cryogenic Engineering Conference has been held in Boulder, Colorado, and has been hosted by the University of Colorado's College of Engineering and the National Bureau of Standards Boulder Laboratories. In presenting the papers of this ninth national conference, the 1963 Cryogenic Engineering Conference expresses its thanks to these two hosts for the fine cooperation that has existed between these organ i- zations with regard to both cryogenic research and conference activity. Since the Cryogenic Engineering Conference was first initiated in Boulder in 1954 by R. B. Scott, present Manager of the NBS Boulder Laboratories, it is only fitting that this volume of the Advances in Cryogenic Engineering be dedicated to hirn. The 1963 Cryogenic Engineering Conference Committee also gratefully acknow- ledges the assistance of an Editorial Committee both in selecting papers for the program and in carefully reviewing the final papers for this volume. Participants in this thankless task inc1uded R. W. Arnett, V. D. Arp, P. L. Barrick, D. A. Burgeson, D. B. Chelton, R. S. Collier, J. W. Dean, T. M. Flynn, R. N. Herring, M. J. Hiza, J. Hord, J. G. Hust, V. J. Johnson, F. Kreith, R. H. Kropschot, P. R. Ludtke, D. B. Mann, R. D. McCarty, L. MuHen, M. T. Norton, R. P. Reed, R. F. Robbins, W. G. Steward, R. B. Stewart, D. H. Weitzel, and W. A. Wilson.

The Cryogenic Engineering Conference celebrated its Silver Anniversary at the 1979 Conference held at Madison, Wisconsin. For many it provided an opportunity to reminisce about the first Cryogenic Engineering Conference convened at the National Bureau of Standards in Boulder, Colorado and also about the many following conferences and advances that had been reported at these conferences. It is difficult to realize that the first Cryogenic Engineering Conference was held before the advent of multilayer insulation, the space age, large-scale LNG Operations and superconductivity applications. The evolution of these activities has been carefully recorded in past volumes of the Advances in Cryogenic Engineering. . Once again, the Cryogenic Engineering Conference is happy to have had the International Cryogenic Materials Conference cohost this meeting at the University of Wisconsin. Collaboration between these two conferences has proven to be mutually beneficial by providing the cryogenic engineer with an in-depth exposure to materials properties, selection, and utilization to complement the exposure to new applications and design concepts. The papers presented at this joint conference as part of the International Cryogenic Materials Conference will be published as Volume 26 of the Advances in Cryogenic Engineering.

The 1961 Cryogenic Engineering Conference Committee is pleased to present the papers of the 1961 Cryogenic Engineering Conference. We are grateful to have had the University of Michigan at Ann Arbor, Michigan as our host for the seventh annual meeting of this group. The Conference Committee in presenting the papers oftbis Conference takes this opportunity to acknowledge the assistance of an Editorial Committee in the selection of papers for the program. Since over one hundred and twenty papers were submitted, their task of screening and evaluating the papers was a dif ficult one. The Committee guided by G. j. V an Wylen, who also served as chair man of the Conference Committee, included R. W. Arnett, B. W. Birmingham, D. B. Chelton, R. j. Corruccini, C. j. Guntner, M. j. Hiza, R. B. jacobs, A. J. Kidnay, R. H. Kropschot, j. Macinko, D. B. Mann, R. P. Mikesell, R. L. Powell, J. R. Purcell, R. P. Reed, R. j. Richards, A. F. Schmidt, R. B. Stewart, and K. A. Warren."

The University of Colorado and the National Bureau of Standards have once again served as hosts for the Cryogenic Engineering Conference in Boulder, Colorado. In presenting the papers of this twelfth annual meeting, the 1966 Cryogenic Engineering Conference Committee has again recognized the excellent cooperation which has existed between these two organizations over the past decade with regard to both cryogenic research and conference activity. This cooperation was demonstrated not only at the 1966 Cryogenic Engineering Conference but also at the International Institute of Refrigeration, Commission I Meeting, which was also hosted by these two organizations immediately following the Cryogenic Engineering Conference. These two meetings have provided attendees with one of the most comprehensive coverages of cryogenic topics that has ever been presented at one location. Emphasis on major international advances in helium technology at the International Institute of Refrigeration, Commission I Meeting has been possible largely through the National Science Foundation Grant GK 1116 to the University of Colorado. The Cryogenic Engineering Conference Committee gratefully acknowledges this support because of its valuable international contribution to the Cryogenic Engineering Conference. As in the past, the Cryogenic Engineering Conference Committee is grateful for the continued assistance of all the dedicated workers in the cryogenic field who have contributed their time reviewing the preliminary papers for the program and the final manuscripts for this volume.

The National Bureau of Standards Boulder Laboratories at Boulder, Colorado once again served as the host for the 1972 Cryogenic Engineering Conference. For the Cryogenic Engineering Conference it was like coming horne, for it was at the NBS Boulder Laboratories that the Cryogenic Engineering Conference was first conceived and held m 1954m connection with the dedication ofthe NBS Boulder Laboratories by President Dwight D. Eisenhower. The Cryogenic Engineering Conference IS grateful for the continuing support that the National Bureau of Standards has gIVen over the years, and which was expanded on July 1, 1971 when the NBS Boulder Laboratories assumed the secretariat function of the Conference from the National Academy of Sciences. Because of common interests in heat transfer, the 1972 Cryogemc Engineering Conference worked with the 13th National Heat Transfer Conference to develop a joint program m heat transfer. A majority ofthe papers presented in this cooperative effort are incIuded m V olume 18 of the Advances zn Cryogenic Engineerzng through the kmd permission ofthe 13th NatIOnal Heat Transfer Conference and are acknowl edged accordingly."

The Cryogenic Engineering Conference celebrated its Silver Anniversary at the 1979 Conference held at Madison, Wisconsin. For many it provided an opportunity to reminisce about the first Cryogenic Engineering Conference convened at the National Bureau of Standards in Boulder, Colorado and also about the many following conferences and advances that had been reported at these conferences. It is difficult to realize that the first Cryogenic Engineering Conference was held before the advent of multilayer insulation, the space age, large-scale LNG Operations and superconductivity applications. The evolution of these activities has been carefully recorded in past volumes of the Advances in Cryogenic Engineering. * Once again, the Cryogenic Engineering Conference is happy to have had the International Cryogenic Materials Conference cohost this meeting at the University of Wisconsin. Collaboration between these two conferences has proven to be mutually beneficial by providing the cryogenic engineer with an in-depth exposure to materials properties, selection, and utilization to complement the exposure to new applications and design concepts. The papers presented at this joint conference as part of the International Cryogenic Materials Conference will be published as Volume 26 of the Advances in Cryogenic Engineering.

The 1960 Cryogenic Engineering Conference Committee is pleased to present the papers of the 1960 Cryogenic Engineering Conference. Discussion of the papers, wherever available, has also been included to make the papers more valuable and interesting to the reader. This annual meeting once again has been held in Boulder, Colorado. Many delegates will recall that similar meetings were held in Boulder in 1954, 1956 and 1957. However, this year, because of the continued growth of this conference, the National Bureau of Standards Boulder Laboratories was joined by the College of Engineering of the University of Colorado in hosting this sixth national con ference. The Cryogenic Engineering Conference Committee is happy to acknowledge the help of an Editorial Committee which contributed valuable assistance in the difficult and thankless task of screening the preliminary papers and also re viewing the final drafts. This committee headedby R. B. jacobs, who also served as chairman for the Conference Committee, consisted of R. W. Arnett, D. B. Chelton, R. J. Corruccini, T. M. Flynn, R. H. Kropschot, R. M. McClintock, A. F. Schmidt, L. E. Scott and W. A. Wilson."

1969 marked the return of the Cryogenic Engineering Conference, now affiliated with the National Academy ofSciences through the Division ofEngineering, National Research Council, to the University of California at Los Angeles. As in 1962, the Cryogenic Engineering Conference gratefully acknowledges the assistance of UCLA, its Engineering and Physical Seien ces Extension Division, and in particular J. Dillon, S. Houston, H. L. Tallman, and their stafffor serving as hosts to the 1969 Cryogenic Engineering Conference. The National Academy of Sciences is a private honorary organization of more than 700 scientists and engineers elected on the basis of outstanding contributions to knowledge. Established by a Congressional Act of Incorporation, the Academy works to further science and its use for the general welfare by bringing together the most qualified individuals to deal with scientific and technological problems of broad significance. The National Research Council was organized as an agency of the National Academy of Sciences in 1916, to enable the broad community of U.S. scientists and engineers to associate their efforts with the Iimited membership of the Academy in service to science and the nation. The Division of Engineering is one of the eight major Divisions into which the National Research Council is organized for the conduct of its work. Its membership includes representatives of the nation's leading technical societies as weH as a number of members-at-Iarge. The Cryogenic Engineering Conference is an organization of the Division of Engineering.

The 1965 Cryogenic Engineering Conference, in presenting the papers of its eleventh annual meeting takes this opportunity to gratefuIly acknowledge the assistance of Rice University and, in particular, R. Kobayashi and his staff for serving as hosts for this conference. This meeting, because of its proximity to the NASA Manned Spacecraft Center, has recognized the impact of the space age on the cryogenic field and has, there fore, attempted to emphasize this aspect of cryogenics to a greater degree than in past conferences. The highlight of this conference has been the presentation of the highest Cryogenic Engineering Conference award-The Samuel C. CoIlins Award-to its first recipient, Dr. Samuel C. Collins. This award, set up in his name, has recognized the outstanding contributions that Dr. S. C. CoIlins, retired Professor of Mechanical Engineering at the Massachusetts Institute of Technology, has made in the field of helium liquefaction. His significant advances in various phases of cryogenics have been recognized inter nationaIly by numerous organizations. High on this list has been the tribute which was bestowed on hirn by the Kamerlingh-Onnes Laboratory in Leiden in awarding hirn the first Kamerlingh-Onnes gold medal to an American in 1958. The Cryogenic Engineering Conference, in addition to recognizing his pioneering work in helium liquefaction by the presentation of the Samuel C. Collins Award, also dedicates this volume of the Advances in Cryogenic Engineering to hirn."

The 1959 Cryogenic Engineering Conference Committee is pleased to pre sent the papers of the 1959 Cryogenic Engineering Conference. We are fortunate to have had the University of California at Berkeley, Ca ., as our host for the fifth national meeting of this kind. The move to the West Coast for this past Cryogenic Engineering Conference was prompted in part by the large concentration of missile activities which are to be found there. Recognition of cryogenic operations and techniques in the mis sile field is given in many of the included papers. The University of California was certainly wen suited for such a meeting as this because it was here that much early work was done in cryogenics. This pioneering in cryogenics is still evident today in the operation of the 72-in. bub ble chamber at the Lawrence Radiation Laboratory. The Cryogenic Engineering Conference salutes the missile industry and the cryogenic pioneers of yesterday and today at the University of California. Special thanks must go to Dr. D. N. Lyon from the Low-Temperature Laboratory of the University of California, who as chairman of the 1959 Cryogenic Engineering Conference Committee has worked tirelessly to increase the stature of this conference. vii ACKNOWLEDGMENT The Cryogenic Engineering Conference Committee is deeply grateful for the continued support and interest of the following organizations who made the 1959 Cryogenic Engineering Conference possible. Aerojet-General Corporation A. D. Little, Inc."

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.

Support from the National Science Foundation has made it possible for the tenth annual Cryogenic Engineering Conference, hosted by the University of Pennsylvania and capably directed by K. R. Atkins and his staff, to emphasize the major international advances in cryogenic engineering. This specific emphasis resulted in a final program of over one hundred papers and has made it necessary to publish the proceedings of the conference in two volumes. The first volume will be similar in nature to previous volumes in this series, while the second volume will feature the international aspect of the conference program. The latter volume, because of this distinction, will be entitled International Advances in Cryogenic Engineering. As in the past, the Cryogenic Engineering Conference Committee gratefully acknow ledges the assistance of all the dedicated workers in the cryogenic field who have contributed their time in reviewing the preliminary papers for the program and the final manuscripts for this volume. Since the list of participants in this thankless task numbers well over one hundred, any attempt to acknowledge their individual contributions in the limited space available would be practically impossible."

1970 marked the seventh return of the Cryogenic Engineering Conference, now affiliated with the National Academy of Sciences through the Division of Engineering, National Research Council, to Boulder, Colorado. Local arrangements for this year's meeting have again been capably handled by the University of Colorado and the Cryogenics Division, NBS Institute for Basic Standards. The Cryogenic Engineering Conference Committee gratefully acknowledges the assistance of these two organizations, and particularly the Bureau of Continuation Education of the University of Colorado, for serving as hosts to the 1970 Cryogenic Engineering Conference. The National Academy of Sciences is a private, honorary organization of more than 700 scientists and engineers elected on the basis of outstanding con tributions to knowledge. Established by a Congressional Act of Incorporation signed by Abraham Lincoln on March 3, 1863, and supported by private and public funds, the Academy works to further science and its use for the general welfare by bringing together the most qualified individuals to deal with scientific and tech nological problems of broad significance. Under the terms of its Congressional charter, the Academy is also called upon to act as an official-yet independent adviser to the Federal Government in any matter of science and technology. This provision accounts for the close ties that have always existed between the Academy and the Government, although the Academy is not a governmental agency and its activities are not limited to those on behalf of the Government."

By popular request, the National Bureau of Standards was again a host to a conference on cryogenic engineering on August 19-21, 1957. Similar meetings were held here in 1954 and 1956. The acceptance of over forty papers for this conference was certainly a sign of the increasing activity and interest in this engineering field. There seems little doubt that it will continue to grow, justifying the need for annual meetings. To make the Proceedings more interesting an attempt was made to include as much as possible of the general discussion which followed each paper. To obtain individual reprints of anyone particular paper, please contact the authors directly. 1957 CRYOGENIC ENGINEERING CONFERENCE COMMITTEE B. W. Birmingham National Bureau of Standards S. C. Collins Massachusetts Institute of Technology E. F. Hammel Los Alamos Scientific Laboratory R. B. Scott National Bureau of Standards K. D. Timmerhaus University of Colorado W. T. Ziegler Georgia Institute of Technology i ACKNOWLEDGMENTS The 1957 Cryogenic Engineering Conference Committee gratefully acknowledges the continued support and interest of the following organizations who have made the 1957 Cryogenic Engineering Conference and the publication of this Proceedings possible. L' Air Liquide Air Products, Inc. Allison Division, General Motor s American Messer Corporation Aro Equipment Corporation Beech Aircraft Corporation Bell Aircraft Boeing Airplane Company Cambridge Corporation Convair Curtiss-Wright Corporation Garrett Corporation General Electric Company Herrick L. Johnston, Inc. Hofman Laboratories Linde Company A. D. Little, Inc.

The 13th International Conference on Low Temperature Physics, organized by the National Bureau of Standards, Los Alamos Scientific Laboratory, and the University of Colorado, was held in Boulder, Colorado, August 21 to 25, 1972, and was sponsored by the National Science Foundation, the U. S. Army Office of Scientific Research, the U. S. Atomic Energy Commission, the U. S. Navy Office of Naval Research, the International Institute of Refrigeration, and the Internation al Union of Pure and Applied Physics. This international conference was the latest in a series of biennial conferences on low temperature physics, the first of which was held at the Massachusetts Institute of Technology in 1949. (For a complete list of previous L T conferences see p. viii. Many of these past conferences have been coordinated and sponsored by the Commission on Very Low Temperatures of IUPAP. Subsequent LT conferences will be scheduled triennially beginning in 1975. LT 13 was attended by approximately 1015 participants from twenty five countries. Eighteen plenary lectures and 550 contributed papers were presented at the Conference. The Conference began with brief introductory and welcoming remarks by Dr. R. H. Kropschot on behalf of the Organizing Committee, Professor J. Bardeen on behalf of the Commission on Very Low Temperatures of the IUP AP, and Pro fessor O. V. Lounasmaa on behalf of the International Institute of Refrigeration. The eighth London Award was then presented by Professor E."

1971 marked the first year since 1956 that the annual Cryogenic Engineering Conference was not held. Instead, the Cryogenic Engineering Conference gave its full support to the XIII International Congress of Refrigeration by working with Commissions I and II of the International Institute of Refrigeration to organize the cryogenic sessions for these two commissions. All of the papers presented at the International Congress of Refrigeration will be published by the IIR as part of the proceedings of that meeting. Even though no Cryogenic Engineering Conference was held in 1971, it became quite evident to the Conference Board that there were sufficient advances in cryogenic engineering to warrant the publication of Volume 17 of the Advances in Cryogenic Engineering. Volume 17 presents the advances in this important field by bringing together in one volume some of the significant papers that have been presented at various technical meetings across the country during the latter half of 1970 and the first part of 1971. In addition, several authoritative review papers have been prepared by invitation of the Cryogenic Engineering Conference Board.

The National Bureau of Standards Boulder Laboratories was on September 5-7, 1956 again host to a national conference on cryogenic engineering. Supported financially by many of the leading industrial firms currently active in this rapidly expanding field, the conference, second of its kind, attracted more than 400 scientists and engineers from all parts of the world. This attendance was evidence of the present interest and growth in cryogenic engineering, a field which has as yet not found a satisfactory place within the bounds of existing professional societies. In all but two cases the Proceedings contain the summary or entire text of the paper presented at the confer ence. Forty-nine papers were presented at seven separate sessions. These sessions were divided into the following general topics: Cryogenic Processes Cryogenic Equipment Cryogenic Properties Cryogenic Applications Bubble Chambers The division in some cases had to be somewhat arbitrary since several papers could have been classified under more than one general topic. To make the Proceedings more valuable to the reader, an attempt was made to record the general discussion which followed each paper. Unfortunately, however, the recording devices were not sensitive enough for clear reproduction. The discussions, therefore, have not been included in the Proceed ings."

More than sixty years have elapsed since Linde first liquefied air on a commercial scale and prepared the way for separating of other gaseous mixtures. His work, however, was not of an isolated nature. It was conceived eighteen years after air had, for the first time, been liquefied in the laboratory by Pictet in Geneva and Caillete in Paris. Linde's liquefaction of air was followed by Dewar's work on hydrogen liquefaction in London and by the setting up at Leiden of Kamerlingh Onnes's famous low temperature laboratory. These advances in low temperature or cryogenic technology have resulted in the establishment of a completely new and thriving industry. Cryogenic engineering is concerned with developing and improving low temperature processes, techniques, and equipment; determining the physical properties of structural and related materials used in producing, maintaining, and using low temperatures; and the practical application of low temperature techniques and processes. These low tempera tures are below those usually encountered in refrigerating engineering. It is rather difficult to assign a definite temperature which serves to divide refrigerating engineering from cryogenic engineering. A temperature below _lSOoC, however, is generally associated with cryogenic engineering."