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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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Cold Compressors

A common way to provide cooling below the normal boiling point of helium (4.2K) is to reduce the pressure above the bath of liquid helium, thus also reducing the bath’s equilibrium saturation temperature. For example, to produce a 1.8K bath of liquid helium, the saturation pressure has to be reduced...

Kapitza Conductance

Kapitza conductance refers to the heat transfer between a solid surface and a fluid that covers that surface. Fundamentally, it describes the inherent difficulty in transferring energy from a solid to the fluid covering the solid surface. This phenomenon was first observed by P. L. Kapitza in 1941 while studying...

Thermosyphons

A thermosyphon (or thermosiphon) is a device that transfers heat via natural convection in a fluid. The natural convection is driven by gravity with the colder, denser fluid flowing downhill and the warmer, less dense fluid flowing back up. Thus, thermosyphons connect an object to be cooled with a reservoir...

Air Separation and Liquefaction

by Nils Tellier, PE, President, EPSIM Corporation (CSA CSM) nils@epsim.us All illustrations courtesy EPSIM Corporation Background History of Air Separation and Liquefaction This section builds on a rich history of methods to develop deep refrigeration and cryogenic liquefaction during the 19th Century. You are encouraged to read Cryo Central’s History...

Bose-Einstein Condensate

A Bose-Einstein condensate, first proposed in 1925 by Albert Einstein based on work done by Satyendra Nath Bose (the same Bose from whom the term boson is derived), is a super-cold state of matter in which almost all of the individual atoms have “condensed” down to the lowest possible quantum...

Cold Technology for Pest Control

While it does not reach temperatures cold enough to be called cryogenic, carbon dioxide snow is at the heart of a new way of dealing with unwanted pests. It utilizes a quick freezing process that takes advantage of the properties of carbon dioxide snow and has a number of benefits...

Cryogenic Finishing

The following 3 articles discuss the uses and procedures of various type of cryogenic finishing. 1) By Robin A. Rhodes, Cryogenic Institute of New England, Inc. rrhodes@nitrofreeze.com Cryogenic Deflashing is employed to remove undesired residual mold flash that remains on molded parts after they are removed or ejected from the...

In search of a calculation for designing a cryostat

I am a final year physics student at the University of Birmingham, and as part of a group I am currently designing a cryostat. One of the calculations I need to make (very soon!) is how much heat will be conducted down the walls. All information I have found so...

Safety of ethylene glycol and pressurized oxygen

We are reviewing the product design of liquid filled differential level gauges and want to insure that they meet the industry requirements. The former license owner had authorized that a fill fluid of ethylene glycol (68%) and distilled water (32%) could be used for oxygen service up to 500 psi....