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Sealing Options for Aluminum Vacuum Chambers

The goal of any sealing option for a vacuum chamber, whether aluminum or another material, is to provide a leak free (or acceptable leak rate) transition from the interior vacuum of the chamber to the exterior environment. For all types of vacuum chambers these options fall into two broad categories:...

Cool Fuel: Bias and Green versus Blue Hydrogen

I was ready to write about the awesome green beauty of a 454.6 nm argon laser and what it does to the hydrogen molecule when a friend sent me an article from the New York Times by Hiroko Tabuchi, “For many hydrogen is the fuel of the future. New research...

In Memoriam: Peter Mason 1928-2021

We regret to report the passing of former Jet Propulsion Laboratory (JPL) leader, visiting associate at Caltech, CSA Fellow and Cold Facts Space Cryogenics columnist, Peter V. Mason. He passed after a short illness on May 30, 2021.

Qubit Measurement Systems Right Out of the Box?

During past years, advances in both lithography and millikelvin cryogenics have supported and enabled vast improvement in the sophistication of experimental research on electrical circuits that display uniquely quantum mechanical behavior. It comes as no surprise that dilution refrigerator measurement systems have moved beyond basic physics research contraptions and into...

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Stability

Stability refers to the ability of a device employing superconductors to remain in its superconducting state after part of the superconductor transitions back to its normal conducting state due to a disturbance. While the concept can apply to many superconducting devices—transmission lines, generators, motors, etc.—it is most commonly considered in...

Cable-in-Conduit Conductors

Cable-in-Conduit Conductors (CICC) are a common form of superconducting cable used in large-scale applications. There are several varieties of CICCs, but they all consist of many small, stabilized superconducting wires contained within a conduit through which a coolant (typically supercritical He II) flows. Figure 1 shows the cross section of...

Bayonet Coupling

A bayonet coupling is a demountable joint that allows for quick and easy connection and disconnection of cryogenic components, including transfer lines, cryostats, liquefiers and refrigerators. Bayonets provide a number of advantages, chief among them the ability to connect and disconnect the bayonets while components they connect are still at...

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...