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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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Refrigerators and Liquefiers

Two of the most common terms used in cryogenics are “refrigerator” and “liquefier.” These terms describe similar and, as will be seen, in some cases identical components. A refrigerator provides cooling (that is, absorbs heat) at cryogenic temperatures. Refrigerators typically put a working fluid (such as helium) through one of...

Air Separation

Air separation is one of the largest, as well as earliest, industrial applications of cryogenics. In this process, cryogenic temperatures are used to separate air into its constituent gases: nitrogen (78.08%), oxygen (20.95%), argon (0.93%) and carbon dioxide (0.3%). Trace gases such as krypton, neon, xenon and helium total far...

Coefficient of Performance and Figure of Merit

The coefficient of performance (COP) is used to describe the effectiveness of refrigerators, including those operating at cryogenic temperatures. The COP is defined as the amount of heat removed at the cryogenic operating temperature of the refrigerator divided by the amount of work that must be applied to remove the...

Wind Tunnels

Dr. Robert Kilgore The development of the cryogenic wind tunnel is one of many significant breakthroughs in both cryogenics and wind-tunnel technology made during the past millennium. Interest in the development of high-speed commercial and military aircraft resulted in a review of problems of flow simulation in transonic wind tunnels...

History of Cryogenics

From the Fall 1999 issue of Cold Facts magazine Millennium Breakthroughs A variety of CSA members give different perspectives on the past millennium: What were the most significant breakthroughs in cryogenics during the past millennium? Prof. R.G. Scurlock, Kryos Technology, scurlock@soton.ac.uk (“Breakthrough” = way through obstacles — Oxford English Dictionary)...

Cryobiology

Andreas Sputtek Past President Society for Cryobiology sputtek@uke.uni-hamburg.de or http://www.sputtek.de/. The word cryobiology (from the Greek words “cryo” = cold, “bios” = life, and “logos” = science) literally signifies the science of life at low temperatures. In practice, this field comprises the study of any biological material or system (e.g.,...

Cryogenic Insulation

James E. Fesmire Cryogenics Test Laboratory NASA Kennedy Space Center james.e.fesmire@nasa.gov Introduction In today’s world, the use of cryogenics and low-temperature refrigeration is taking a more and more significant role. From the food industry, transportation, energy, and medical applications to the Space Shuttle, cryogenic liquids must be stored, handled, 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...