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Space Systems Command Grants Contracts for Space Laser Communication Prototypes

The EST program, part of SSC’s Space Domain Awareness and Combat Power Program Executive Office, aims to create on-orbit crosslink compatibility among future space systems. This will be achieved through a standardized enterprise waveform implemented in a long-range space optical communications terminal that is low in size, weight, power, and...

Fusion Power Is Now a Possible Dream

Fusion power, the Holy Grail of nuclear energy for decades, may finally be within our grasp. If the scientists and engineers at Commonwealth Fusion Systems (CFS), a company with close ties to the Massachusetts Institute of Technology Plasma Science and Fusion Center, are right, fusion is nearly ready for power market...

Atomic Spreading Produces Novel Superconductors

Custom layering. A single layer of the topological insulator WTe2 (green) was placed on top of a row of palladium seeds (each roughly 0.5 µm wide). Over time, palladium atoms spread out across the layer and formed Pd7WTe2 (blue-green). The sample is shown before heating (left), after 25 minutes at 210 °C (center),...

100 Years of Quantum Is Just the Beginning

Recognizing the importance of quantum science and the need for wider awareness of its past and future impact, dozens of national scientific societies gathered together to support marking 100 years of quantum mechanics with a U.N.-declared international year. The timeline of endorsements for this international year also included the International Union of Pure and...

Cool It Down–Isochoric Preservation

If you’ve ever made the mistake of putting certain fresh fruits or vegetables in the freezer, then you’re already familiar with the effects of freezing on biological tissue. Banana skins turn black and slimy. Whole oranges leak and deflate. Lettuce comes out limp and soggy. The cause of all this...

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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....

Food Processing

Cryogenics and Food The industrial gas industry provides a host of products and services related to food. The various gases have useful and sometimes fascinating applications in food industry. “The food industry is not a homogenous industry. The needs of customers processing hamburger vs. poultry vs. strawberries vs. seafood, for...

Primary Standards

Elie K. Track Hypres, Inc. elie@hypres.com http://www.hypres.com/ Primary standards involve the exact definition and realization of units of measurement for various quantities, time, length, mass, voltage, resistance, current, etc. International agreements based on the latest scientific knowledge define those units, and their realizations vary depending on the unit itself. For...

Shrink Fitting

Robin A. Rhodes Cryogenic Institute of New England, Inc. rrhodes@nitrofreeze.com Shrink fitting, (or “compression fitting” as it is sometimes called), is a method used to insert a pin or bushing into a housing or other assembly requiring an extremely tight tolerance fit. It can be used as an alternative to...

Telecommunications

From the Winter 2004 issue of Cold Facts magazine The recent M-Calc IV — 4th Industry Assessment workshop discussing military and commercial applications for low-cost cryocoolers, held in November in San Diego, highlighted progress being made in cryogenics as applied in telecommunications. The reliability and long lifetime of projects now...

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...