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The Next Niobium Goal: Medium-Field SRF Cavities with High Quality Factor

In his guest column, Dr. Lance Cooley writes, "We are now beginning to evolve our present knowledge about producing high-gradient cavities to take on goals of high-Q CW cavities. The starting point for this transition is clearly to explore simple adaptations of the present ILC process. But it is not...

American College of Cryosurgery Holds Annual Meeting

The American College of Cryosurgery, founded in 1977, hosted its first meeting January 2-7, 2013, after a hiatus of nearly ten years. The meeting venues provided a unique experience for participants and accompanying guests. A land-based session was held at the Hyatt Regency Downtown Miami Hotel.

Donnelly Team Designs Cryogenic Remediation of Power Pollutants

Professor John M. Pfotenhauer writes, "The fields of low temperature physics and energy and environment do not frequently interact. Imagine my astonishment to find in the 2010 spring edition of a newsletter from the Department of Physics at my graduate school, the University of Oregon, that my thesis advisor from...

Cryo Community Mourns Donna Jung, International Cryogenics

It is with great regret that we report the sudden death of Donna Jung, President of International Cryogenics, on February 1, 2013. Jung was a leader in the cryogenic community, president of a longtime CSA Corporate Sustaining Member company, and a stalwart supporter of the Society. Jung, 52, was one...

Rules of thumb for the design length of transition tubes

Are there any rules of thumb for the design length of transition tubes in order to prevent condensation at the room temperature end? By “transition tube,” I mean some standard size (O.D. and wall thickness) type 304 stainless steel tube with either 4 K or 80 K at one end...

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Mixed Refrigerant Cycles

Most cryogenic refrigeration systems, both large scale systems and cryocoolers, use helium as a working fluid. There are a number of advantages to helium, not the least of which is that helium remains a fluid down to the lowest achievable temperatures. In order to freeze helium, pressures of over 20...

Fountain Pumps and He II Phase Separators

Helium II (He II), the second liquid phase of the 4He isotope described in this column in Cold Facts Spring 2010 (http://2csa.us/he2), can be modeled as consisting of two interpenetrating fluids. One, the superfluid component, has zero viscosity and entropy and the other, the normal fluid component, has nonzero viscosity...

Turboexpanders

A vital technology in the refrigerators and liquefiers described in Cold Facts Volume 31 Number 3 is that of turboexpanders. These devices are rotating machines in which the process fluid (e.g., helium) does work against the turboexpander while moving from high pressure to a lower pressure and thus is cooled....

Cryogenic Treatment of Materials

F.J. Diekman Controlled Thermal Processing, Inc. info@metal-wear.com Cryogenic Processing (also called cryogenic treatment, and incorrectly “cryogenic tempering”) is a process that uses cryogenic temperatures to modify materials to enhance their performance. Cryogenic Processing involves the slow reduction in temperature of the material to at least -300°F (-185°C) and holding the...

Cryogenics in Space

Peter Kittel University of California-Berkeley pkittel@cal.berkeley.edu Space Cryogenics is the application of cryogenics to space missions. These applications fall into two broad areas, supporting space science missions and supporting the space transportation infrastructure. Science applications: The atmosphere is opaque to much of the electro-magnetic spectrum. In space, the absence of...

Cryosurgery

Review of Cryosurgery Boris Rubinsky, PhD Hebrew University School of Science and Engineering Research Center for Biomedical Engineering 78b Ross Building Givat Ram, Jerusalem 91904 Israel rubinsky@cs.huji.ac.il as published in Annual Review of Biomedical Engineering, August 2000, Vol. 2, pp. 157-187. Abstract: Cryosurgery is a surgical technique that employs freezing...

Liquefied Natural Gas

Liquefied Natural Gas as it relates to the Field of Cryogenics John W. Bonn VJ Systems, LLC johnbonn@vjsystems-lic.com Today the world is looking for a cleaner fuel and Liquefied Natural Gas (LNG) plays a large part in achieving this goal. LNG in a liquid form is at -162°C (-259°F) and...

An Issue of Pressure and Flow Rate in a Supply Tank

Please help solve this problem: A supply tank requires a vaporizer to generate sufficient pressure to pump stored fluid up into a vehicle or tank. The available head is limited as the tank level falls and it is important to minimize the system pressure drop to maintain the desired flow...

Using MLI on VJ Line Joints or Cryo Storage Tanks

When installing Multi Layer Insulation (MLI) blankets on VJ line joints or cryo storage tanks should they be wrapped and tied down tight or loose? These are usually pre-cut to size. Also should they have an access hole at the point of where the molecular sieve is installed to help...